List of
speakers (in alphabetical order)

Goro Akagi, Traveling wave dynamics for a onedimensional constrained AllenCahn equation ,
Monday, 13 September 2021.

Mark Ashbaugh, A FaberKrahn Result for the Vibrating Clamped Plate under Compression ,
Monday, 28 February 2022.

Sandra Cerrai, Incompressible viscous fluids in the plane and SPDEs on graphs.,
Monday, 22 November 2021.

Beomjun Choi, Liouville theorem for surfaces translating by subaffinecritical powers of Gauss curvature,
Monday, 27 September 2021.

ChiunChuan Chen, Traveling wave solutions for the diffusive LotkaVolterra system of 3 competing species,
Monday,15 November 2021.

Florica Cirstea, Anisotropic elliptic equations with gradientdependent lower order terms and \(L^1\) data,
Monday, 20 September 2021.

Cristiana De Filippis, Perturbations beyond Schauder data,
Monday, 8 November 2021.

Serena Dipierro, Boundary
behaviour of nonlocal minimal surfaces,
Monday, 22 February 2021.

Yihong Du, Spreading rate for the FisherKPP nonlocal diffusion equation with free boundary ,
Monday, 31 May 2021.

Renjun Duan, Lowregularity solutions to the noncutoff Boltzmann equation: existence, regularity and grazing limit ,
Monday, 28 March 2021.

Ilaria Fragala, Concavity properties of solutions to Robin problems ,
Monday, 5 July 2021.

Rupert Frank, Blowup of solutions of critical elliptic equations in three dimensions ,
Monday, 10 May 2021.

Nicola Garofalo, A heat equation approach to some problems in conformal geometry.,
Monday, 19 July 2021.

Emanuela Gussetti, A pathwise stochastic LandauLifschitzGilbert equation via
rough paths in 1D.,
Monday, 16 May 2022.

François Hamel, Symmetry properties for the Euler equations and semilinear elliptic equations,
Monday, 12 April 2021.

InJee Jung, Illposedness for incompressible fluid models at critical Sobolev regularity,
Monday, 26 April 2021.

Yoshiyuki Kagei, Stability
and bifurcation analysis of the compressible NavierStokes equations,
Monday, 8 March 2021.

Derek Kielty, Degeneration of the spectral gap with negative Robin parameter.,
Monday, 30 August 2021.

Minhyun Kim, Nonlocal problems with nonstandard growth ,
Monday, 6 December 2021.

Sunghan Kim, Uniform regularity in homogenization problems of fully nonlinear equations ,
Monday, 14 March 2022.

WeiXi Li, Gevrey wellposedness of the 3D Prandtl equations without Structural Assumption ,
Monday, 26 July 2021.

Yuan Lou, On principal eigenvalues for elliptic and parabolic operators ,
Monday, 1 November 2021.

Tao Luo, Estimates and geometry for a free surface problem of fluids with heatconductivity ,
Monday, 17 May 2021.

Yasunori Maekawa, Recent progress on the Prandtl boundary layer expansion for viscous incompressible flows ,
Monday, 14 June 2021.

Shuang Miao, On the
free boundary hard phase fluid in Minkowski spacetime,
Monday, 15 February 2021.

Tatsuya Miura, LiYau type inequality for curves and applications,
Monday, 6 September 2021.

Yoichi Miyazaki, A tour of Sobolev spaces by Muramatu's integral formula,
Monday, 11 October 2021.

Monica Musso, Vortex filaments for Euler equations ,
Monday, 25 October 2021.

Toru Nogayama, Maximal regularity in BesovMorrey spaces and its application to KellerSegel System,
Monday, 12 July 2021.

Aaron Palmer, Hidden Convexity in
problem of Nonlinear Elasticity,
Monday, 22 March 2021.

Naoto Shida, Bilinear pseudodifferential operators with exotic symbols,
Monday, 7 March 2022.

Ken Shirakawa, Temperature optimization problems governed by semidiscrete phasefield models of grain boundary motions ,
Monday, 14 February 2022.

Adam Sikora, Square functions and Riesz transforms on a class of nondoubling manifolds ,
Monday, 21 June 2021.

Mitsuru Sugimoto, A constructive
approach to semilinear wave equations,
Monday, 25 January 2021.

Yutaka Terasawa, Convergence of a Nonlocal to a Local Diffuse Interface Model for
TwoPhase Flow with Unmatched Densities,
Monday, 10 May 2022.

Emmanuel Trélat, Spectral
analysis of subRiemannian Laplacians and Weyl measure,
8, February 2021.

Po Lam Yung, Sobolev spaces revisited,
29, November 2021.

Zhifei Zhang, Linear inviscid damping and enhanced dissipation for shear flows,
24, January 2022.

Rongchan Zhu, Large \(N\) Limit
of the \(O(N)\) Linear Sigma Model via Stochastic Quantization,
Monday, 25 January 2021.

Enrique Zuazua, Inverse design for conservation laws and HamiltonJacobi equations,
Monday, 21 March 2022.
See also the Talks in 2020 page.
Monday, 16 May 2022.
PhD student @ University of Bielefeld, Germany
Emanuela Gussetti is currently a Phd student at the University of
Bielefeld (Germany), under the supervision of Professor Martina
Hofmanová. She completed her Master degree at the University of Milan
(Italy). Her main research interests are in the application of rough
path for the study of stochastic PDEs.
Slides to the talk

A pathwise stochastic LandauLifschitzGilbert equation via
rough paths in 1D
Using a rough path formulation, we investigate existence,
uniqueness and regularity for the stochastic LandauLifshitzGilbert
equation with multiplicative Stratonovich noise on the one dimensional
torus. As a main result we show the Lipschitz continuity of the
socalled ItôLyons map in the energy spaces
\(L^\infty(0,T;H^k)\cap L^2(0,T;H^{k+1})\) for any \(k \ge 1\). As a consequence
we then deduce a WongZakai type result, a large deviation principle for
the solution and a support theorem. At the end of the talk, I will
discuss some recent results.
The talk is based on a joint work with
Antoine Hocquet.
video of the talk coming soon

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Monday, 9 May 2022.
Associate Professor @ Nagoya University, Japan
Yutaka Terasawa obtained a doctor degree in Science in Hokkaido
University in Japan in 2007
under supervision by Tohru Ozawa and Yoshikazu Giga.
He got a JSPS Research Fellowships for Young Scientists (DC2 and PD)
from 2006 to 2008,
by which he collaborated with Helmut Abels in
Stefan Müller's group in Max Planck Institute for Mathematics in the
Applied Sciences in Leipzig.
After that, he spent six months further as a postdoc fellow at the same
institute,
three months in Université ParisEstMarnelaVallée in Paris
and three months in Charles University in Prague from 2008 to 2009.
He became a research assistant in Tohoku University in 2009.
In 2010, we was a specially appointed researcher at the University of Tokyo.
Terasawa received the JSPS Research Fellowship for Young Scientists (PD) in 2011,
and in 2013, he was appointed as assistant professor in 2013 at the University of Tokyo.
Since 2014, he is appointed as associate professor at the Graduate School of
Mathematics of the Nagoya University in Japan. His main research interest is
in mathematical analysis of incompressible fluids, especially diffuse
interface models of twophase flow, harmonic analysis and probability
theory.
Slides to the talk

Convergence of a Nonlocal to a Local Diffuse Interface Model for
TwoPhase Flow with Unmatched Densities
We prove convergence of suitable subsequences of weak solutions of a
diffuse interface model for the twophase flow of incompressible fluids
with different densities with a nonlocal CahnHilliard equation to weak
solutions of the corresponding system with a standard ``local''
CahnHilliard equation. The analysis is done in the case of a
sufficiently smooth bounded domain with noslip boundary condition for
the velocity and Neumann boundary conditions for the CahnHilliard
equation. The proof is based on the corresponding result in the case of
a single CahnHilliard equation and compactness arguments used in the
proof of existence of weak solutions for the diffuse interface model.
This talk is based on a recent joint work with Helmut Abels (Regensburg
Univ., Germany).
video of the talk coming soon

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Monday, 28 March 2022.
Professor @ The Chinese University of Hong Kong, Hong Kong
Professor Duan received his PhD in 2008 at City University of Hong Kong under the supervision of Professor Tong Yang. After graduation, he spent two years as a postdoctoral fellow at RICAM, Austrian Academy of Sciences. From 2010 to present, he has been in the Chinese University of Hong Kong. He was appointed to be an Associate Professor in 2018. His research interest mainly focuses on kinetic theory, in particular, Boltzmann equation and related kinetic equations.
Slides coming soon

Lowregularity solutions to the noncutoff Boltzmann equation: existence, regularity and grazing limit
The Wiener algebra is the space of all integrable functions on torus
whose Fourier series are absolutely convergent. In the talk, we will
present an application of the Wiener algebra to the mathematical study
of the noncutoff Boltzmann equation on torus. We develop a complete
\(L^2\) theory in the
closetoequilibrium framework for global existence, uniform Gevrey
regularity and grazing collision limit of lowregularity solutions to
the Cauchy problem on the noncutoff Boltzmann equation.
video of the talk coming soon

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Monday, 21 March 2022.
Humboldt Professor @ FriedrichAlexanderUniversität ErlangenNürnberg, Germany, Professor @ Universidad Autónoma de Madrid, Spain,
Director of CCM @ University of Deusto, Spain
Enrique Zuazua Iriondo (Eibar, Basque Country – Spain, 1961) holds the
Chair of Dynamics, Control and Numerics – Alexander von Humboldt Professorship at FAU Friedrich–Alexander University, Erlangen–Nürnberg (Germany).
He also leads the research project "DyCon: Dynamic Control", funded by the ERC – European Research Council
at the Department of Mathematics, at UAM – Autonomous University of Madrid and Deusto Foundation,
University of Deusto – Bilbao (Basque Country, Spain), where he holds secondary appointments
as Professor of Applied Mathematics (UAM) and Director of CCM – Chair of Computational Mathematics (Deusto).
His research in the area of Applied Mathematics covers topics in Partial Differential Equations, Systems Control, Numerical Analysis and Machine Learning, and led to fruitful collaborations in different industrial sectors such as the optimal shape design in aeronautics, the management of electrical and water distribution networks and the design of recommendation systems.
His research had a high impact (hindex 44) and he has mentored a significant number of postdoctoral researchers and coached a wide network of Science managers.
He holds a degree in Mathematics from the University of the Basque Country, and a dual PhD degree from the same university (1987) and the Université Pierre et Marie Curie,
Paris (1988). In 1990 he became Professor of Applied Mathematics at the Complutense University of Madrid, to later move to UAM in 2001.
He has been awarded the Euskadi (Basque Country) Prize for Science and Technology 2006 and the Spanish National Julio Rey Pastor Prize 2007 in Mathematics and Information
and Communication Technology and the Advanced Grants NUMERIWAVES in 2010 and DyCon in 2016 of the European Research Council (ERC).
He is an Honorary member of the Academia Europaea and Jakiunde,
the Basque Academy of Sciences, Letters and Humanities, Doctor Honoris Causa from the Université de Lorraine in France and Ambassador of the FriedrichAlexander University, ErlangenNürenberg, Germany.
He was an invited speaker at ICM2006 in the section on Control and Optimization.
From 19992002 he was the first Scientific Manager of the Panel for Mathematics within the Spanish National Research Plan and the Founding Scientific Director of the BCAM – Basque Center for Applied Mathematics from 20082012.
He is also a member of the Scientific Council of a number of international research institutions such as the CERFACS in Toulouse, France and member of the Editorial Board in some of the leading journals in Applied Mathematics and Control Theory.
Slides to the talk

Inverse design for conservation laws and HamiltonJacobi equations
We discuss the problem of inverse design, or time inversion, for scalar conservation laws and HamiltonJacobi equations. The presence of singularities in the forward evolution is an obstruction for backward uniqueness and the unilateral bounds generated by the forward dynamics establishe thresholds on the set of reachable data. In this lecture we shall present our recent works in collaboration with Thibault Liard and Carlos Esteve, characterising the set of reachable states, identifying the multiplicity of initial data leading to a final target, and the determining the role of backward entropy or viscous solutions. We also develop numerical algorithms allowing to reconstruct the set of inversions and present some numerical experiments.
video of the talk coming soon

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Monday, 14 March 2022.
Postdoctoral Fellow @ Uppsala University, Sweden
Dr Kim received his Phd in 2019 @ Seoul National University (Korea) under the supervision of Professor KiAhm Lee. Following this,
he spent one year as a postdoctoral fellow @ KTH Royal Institute of Technology in Stockholm, Sweden. Since 2021, Kim works as a
postdoctoral fellow @ Uppsala University, Sweden.
Slides coming soon

Uniform regularity in homogenization problems of fully nonlinear equations
When two different materials are mixed in small scales, under certain patterns, the effective property of the composite material
in large scales is determined in a nontrivial way. Mathematically, it involves solving a family of equations with rapidly oscillating
variables parameterized by the length of the small scale and studying the behavior of the solutions and the equations at the limit.
Due to certain patterns in the rapid oscillation of the variables, the equation at the limit is usually homogeneous in space. Therefore,
the solution at the limit tends to behave nicely, which makes the solutions close to the limit behave more regular, uniformly in small
scales, than the standard regularity theory ensures, despite the rapid oscillation of the equations at those scales. For this reason,
the uniform regularity in homogenization problems has gained many interests and has contributed to the development of the regularity
theory in various ways. Still, the uniform regularity has only been recently established for fully nonlinear equations.
In this talk, I am going to briefly overview the feature and history of this problem, and introduce the recent results on sharp uniform estimates for fully nonlinear equations.
This talk will be partially based on joint work with KiAhm Lee.
video of the talk coming soon

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Monday, 7 March 2022.
Ph.D. student @ Osaka University, Japan
Naoto Shida is currently Ph.D. student @ Osaka University under the supervision of Professor Naohito Tomita.
He got his Master's degree from Osaka University in 2020.
Slides coming soon

Bilinear pseudodifferential operators with exotic symbols
In this talk, we consider the boundedness of bilinear pseudo
differential operators with symbols
in the bilinear Hörmander class \(BS^m_{\rho, \rho}\), \(0 \le \rho <1\).
First, we consider the case \(\rho =
0\).
In particular, we give an improvement of \(L^2 \times L^2 \to L^1\) boundedness by
using Besov spaces.
Furthermore, we discuss the KatoPonce type inequality (or fractional
Leibniz type rule)
for these operators in the setting of Besov spaces.
Secondly, we give a remark on the condition \(1/p = 1/p_1 + 1/p_2\) for \(L^{p_1} \times L^{p_2} \to L^p\)
boundedness
of those operators. This talk is partially based on a joint work with
Tomoya Kato (Gunma Univ.)
video of the talk coming soon

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Monday, 28 February 2022.
Professor Emeritus @ University of Missouri  Columbia, United States
Professor Ashbaugh received his Ph.D. in Mathematical Physics from Princeton University in 1980,
working under the direction of Barry Simon. He visited @ the University of TennesseeKnoxville
for the 2 years 198082 and has been @ the University of MissouriColumbia since 1982. Ashbaugh has
visited extensively in Chile, most recently as a Fulbright Fellow at the Pontificia Universidad Católica de Chile in Santiago
in 2009 and at the Universidad de Concepción in 2018. Ashbaugh is now an Emeritus Professor of Mathematics,
having retired from the University of Missouri in 2015.
Slides to the talk

Temperature optimization problems governed by semidiscrete phasefield models of grain boundary motions
We give a FaberKrahn result for the first eigenvalue of the vibrating clamped plate under compression,
that is, we show that the lowest eigenvalue of this problem for an arbitrary planar domain \(\Omega\) is bounded
below by that of a disk of the same area for sufficiently small compressions \(\kappa\). Note that this is a result for
\(n=2\) dimensions only, and is sharp. The corresponding result for the vibrating clamped plate (i.e., when \(\kappa = 0\))
was proved by Nadirashvili in 1995 for dimension \(n = 2\), followed quickly by an alternative proof by Benguria
and the speaker that succeeds for dimensions \(n=2\) and \(n=3\) (Duke Math. J., 1995).
This is joint work with R. Benguria and R. Mahadevan. We take a similar approach to that used in the 1995 AshbaughBenguria paper.
Interestingly, the proof does not extend to any \(\kappa > 0\) when \(n = 3\), even though the \(\kappa = 0\) case is known for
\(n = 3\). We explain why this is so.
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Monday, 24 January 2022.
Professor @ Chiba University, Japan
Ken Shirakawa obtained his PhD from Chiba University, Japan, in 2001. He
has been studied mathematical analysis of nonlinear evolution equations,
nonlinear variational problems, nonlinear PDEs, and his recent interest
has been in phase field models of grain boundary motions. He has been an
associate professor at Department of Mathematics, Faculty of Education,
Chiba University, since Oct. 2010.
Slides to the talk

Temperature optimization problems governed by semidiscrete phasefield models of grain boundary motions
In this talk, we consider a class of optimal control problems which
are governed by phasefield systems associated with grain boundary
motions. The statesystems are timediscrete gradient flows, and the
governing energies are based on the freeenergy of planar grain boundary
motions, proposed by [Kobayashi–Warren–Carter, Physica D 140 (2000)]. On
this basis, the principal component of the control is given by the
relative temperature. In the former part of this talk, we discuss about the solvability of the optimal control problems with the wellposedenss
of statesystems; the first order necessary optimality conditions in regular cases of problems; and the limiting approaches to the optimality
conditions in singular cases. Meanwhile, in the latter part, we focus on the 1Dcase of the spatial domain. On this basis, we deal with some
advanced issues, concerned with \(H^2\)regularity of the solutions to
statesystems; precise characterizations of the limiting optimality
conditions.
This talk is based on recent jointwork with Harbir Antil
(George Mason Univ., USA), Shodai Kubota (Chiba Univ., Japan), and
Noriaki Yamazaki (Kanagawa Univ., Japan).
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Monday, 24 January 2022.
Boya Distinguished Professor @ Peking University, China
Zhifei Zhang is a Boya Distinguished Professor at the School of Mathematical Sciences, Peking University. His research interests include the interface problem of the incompressible fluids, mathematical theory of the liquid crystal, hydrodynamic stability at high Reynolds number, and other topics such as the wellposedness of the hydrodynamic equations.
Slides to the talk pending

Linear inviscid damping and enhanced dissipation for shear flows
The inviscid damping and enhanced dissipation play a crucial role in the hydrodynamic stability. Both stabilizing effects are due to the mixing mechanism induced by shear flows. In this talk, I will introduce many approaches developed by some joint works with Q. Chen, T. Li, D. Wei and W. Zhao, to establish the inviscid damping and enhanced dissipation for the linearized NavierStokes system around shear flows including the monotone shear flow and Kolmogorov flow.
Youtube video will release soon

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Monday, 6 December 2021.
Postdoctoral Fellow @ Bielefeld University, Germany.
Dr Kim received his PhD in 2020 from Seoul National University, Korea,
where his supervisor was Prof. KiAhm Lee. Following this, he accepted his first postdoctoral position
at ChungAng University, Korea and since 2021, he is a postdoctoral research fellow at Bielefeld University, Germany.
Slides to the talk pending

Nonlocal problems with nonstandard growth
In the calculus of variations, functionals with nonstandard growth have been studied extensively since the late 1980s. We introduce several nonlocal analogues of these classical models, attempting to develop parallel or unified theory. We study local regularity properties such as local boundedness, weak Harnack inequality, and local Hölder regularity.
Youtube video will release tomorrow

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Monday, 29 November 2021.
Senior Lecturer @ Australian National University in Canberra, Australia.
Professor Yung received his PhD in 2010 @Princton University, United States, under the supervision of Elias Stein. From 20102013, he held the Hill Assistant Professorship @ Rutgers, New Jersey. Following this, we became a Tichmarsh Fellow from 20132014 @ the University of Oxford and Assistant Professorship @ the Chinese University of Hong Kong from 20142020. In 2020, Yung was promoted to Associate Professor @ CUHK while he is on leave. Since 2019, he works as an ARC Future Fellow @ the Australian National University in Canberra. Recently, in 2021, we was awarded the prestigious Antonio Ambrosetti Medal for his new and surpising characterization of the Sobolev norm.
Slides to the talk

Sobolev spaces revisited
In this talk, we will describe some new ways of characterising Sobolev and BV functions, using sizes of superlevel sets of suitable difference quotients. They provide remedy in certain cases where some critical GagliardoNirenberg interpolation inequalities fail, and lead us to investigate real interpolations of certain fractional Besov spaces. Some connections will be drawn to earlier work by Bourgain, Brezis and Mironescu, and an image processing application will be given.
Joint work with Haim Brezis, Jean Van Schaftingen, Qingsong Gu, Andreas Seeger, Brian Street and Oscar Dominguez.
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Monday, 22 November 2021.
Professor @ University of Maryland, United States.
Sandra Cerrai received her Ph.D. in 1998 @ the Scuola Normale Superiore of Pisa, Italy,
under the supervision of Giuseppe Da Prato. She started her academic career @ the
University of Florence. In 2008, she moved to the University of Maryland. She has
served and is still serving on the editorial board of several journals in probability
and PDEs. She has held several visiting positions, among others @ the Newton Institute
in Cambridge, @ the Institute MittagLeffler in Djursholm, @ the MSRI Berkeley, where
she has been Eisenbud Professor, @ the Centre Bernoulli in Lausanne. Professor Cerrai
is currently Simons Fellow in Mathematics.
She is interested in the analysis of systems with multiple scales, that are described
by stochastic partial differential equations. More specifically, she deals with the small
noise asymptotics of those systems, their longtime behavior, averaging phenomena, diffusion
approximation, and singular perturbation results.
Slides to the talk

Incompressible viscous fluids in the plane and SPDEs on graphs
I will present some results about the asymptotic behavior of a class of stochastic
reactiondiffusionadvection equations in the plane. I will show that as the divergencefree
advection term becomes larger and larger, the solutions of such equations converge to the
solution of a suitable stochastic PDE defined on the graph associated with the Hamiltonian.
I will deal with the case that the stochastic perturbation is given by a singular spatially
homogeneous Wiener process taking values in the space of Schwartz distributions. As in previous
works, I will assume that the derivative of the period of the motion on the level sets of the
Hamiltonian does not vanish. Time permitting, without assuming this condition on the derivative
of the period, I will study a weaker type of convergence for the solutions of a suitable class
of linear SPDEs.
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Monday, 15 November 2021.
Professor @ National Taiwan University (NTU), Taiwan.
Dr. ChiunChuan Chen is currently a professor @ National Taiwan University (NTU). He received
his Ph.D. in 1991 from NTU. He held a postdoctoral fellowship at Academia Sinica from 1991 to
1992. From 1992 to 1996, he was a faculty member at National ChungCheng University. In 1996,
he joined NTU and has been a professor there since 1998. He visited Harvard University for one
year during 20072008. He was awarded the National Chair Professorship in 2008. His research
interest mainly focuses on elliptic equations, variational problems, and reactiondiffusion
equations with applications to biology.
Slides to the talk

Traveling wave solutions for the diffusive LotkaVolterra system of 3 competing species
This talk concerns with the 3species LotkaVolterra competition system. Especially we are
interested in a type of traveling wave solutions with a nonmonotone profile. We will describe
some approaches to prove the existence of the waves under suitable parameter ranges. Our results
and related studies indicate that such waves are important in understanding the rich dynamics
of 3 species and may provide a mechanism for species to coexist under strong competition.
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Monday, 8 November 2021.
Assistant Professor @ University of Parma, Italy.
Professor De Filippis recieved her PhD @ University of Oxford (UK) in 2020. Before that, in 2019 she was awarded
the GResearch PhD prize from the UK and the Gioacchino Iapichino Prize from Accademia
Nazionale dei Lincei (Italian national academy). In July 2020, De Filippis accepted a postdoctoral position
@ the University of Turin, Italy. Since 1 November 2021, De Filippis holds a tenure track Assistant Professor
position @ the University of Parma. De Fillippis works in the regularity theory of elliptic
and parabolic partial differential equations and Calculus of Variations.
Slides to the talk

Perturbations beyond Schauder
Socalled Schauder estimates are a standard tool in the analysis of linear elliptic and parabolic PDE.
They had been originally obtained by Hopf (1929, interior case), and by Schauder and Caccioppoli (1934, global estimates).
Since then, several proofs were given, (Campanato, Simon, Trudinger). The nonlinear case is a more recent
achievement from the 80s (Giaquinta \& Giusti, Ivert, Lieberman, Manfredi). All these classical results
hold in the uniformly elliptic framework. I will present recent advances in the nonuniformly elliptic one,
discussing also delicate borderline cases and regularity criteria of interpolative nature.
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Monday, 1 November 2021.
Professor in Mathematical Sciences @ Ohio State University, US.
Dr. Yuan Lou received his bachelor's degree and master's degree from Peking University in 1988 and 1991, respectively. In 1995 he received his Ph.D. from the University of Minnesota. He was a postdoc fellow at MSRI (19951996) and Dickson Instructor at University of Chicago (19961998). Since 1998, he has been a faculty member at Ohio State University. Since 2021, he has been a visiting professor at Shanghai Jiaotong University. Dr. Lou's research interest is reactiondiffusion equations with applications to biology. He has authored 130+ papers on these topics. He served as Associate Director of Mathematical Biosciences Institute (20092013). Currently he is serving as Co EditorinChief of Discrete and Continuous Dynamical SystemsSeries B and in numerous editorial boards, including Journal of Differential Equations, Journal of Math Biology and SIAM Journal of Applied Mathematics.
Slides to the talk

On principal eigenvalues for elliptic and parabolic operators
We will discuss some recent progress on the asymptotic behavior of principal eigenvalues for second order elliptic and timeperiodic parabolic operators. We will mainly focus on the dependencies of principal eigenvalues on diffusion rate and drift rate. Some applications to biology and infectious disease will be presented.
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Monday, 25 October 2021.
Professor @ the University of Barth, UK.
Professor Since February 2018, Monica Musso is a Professor in the Department of Mathematical Sciences @ the University of Bath. Her previous positions were at the Department of Mathematics @ the Universidad Catolica de Chile (since 2004, as professor since 2012) and @ the Politecnico di Torino (since 1999, as Ricercatore in a permanent position). She obtained her PhD in 1997 from the Universita' di Pisa and she was a postdoctoral researcher in the Intenational School for Advanced Studies (SISSA) in Trieste during 1998.
She works in the area of Nonlinear Analysis and Partial Differential Equations (PDEs). Some of the topics she is interested in are Singularity formation in elliptic and parabolic equations, Concentration phenomena in critical problems, and Fractional Yamabe problem.
Slides to the talk

Vortex filaments for Euler equations
We consider the Euler equations for incompressible fluids in 3dimension. A classical question that goes back to Helmholtz is to describe the evolution of vorticities with a high concentration around a cruve. The work of Da Rios in 1906 states that such a curve must evolve by the socalled "binormal curvature flow". Existence of true solutions whose vorticity is concentrated near a given curve that evolves by this law is a longstanding open question that has only been answered for the special case of a circle travelling with constant speed along its axis, the thin vortexrings. In this talk I will discuss the construction of helical filaments, associated to a translatingrotating helix, and of two vortex rings interacting between each other, the socalled leapfrogging. The results are in collaboration with J. Davila (U. of Bath), M. del Pino (U. of Bath) and J. Wei (U. of British Columbia).
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Monday, 11 October 2021.
Professor @ Nihon University, Japan, Japan.
Yoichi Miyazaki was a doctoral student of Professor Tosihusa Kimura at the
University of Tokyo, focusing on spectral asymptotics of elliptic
operators. He became a research associate at Nihon University in 1988,
and received his Ph.D. (Mathematical Sciences) from the University of
Tokyo in 1993. He was promoted to an associate professor in 2013, and a
professor in 2016.
Slides to the talk

A tour of Sobolev spaces by Muramatu's integral formula
In the study of Sobolev spaces Muramatu’s integral formula is very useful. It enables us to prove easily almost all theorems in the theory of Sobolev spaces, if we combine it with basic tools in analysis such as Hölder’s inequality, Minkowski’s inequality, Young’s inequality, and the HardyLittlewood maximal function. Here is a list of the theorems that can be obtained by Muramatu’s integral formula: the Sobolev inequality, the refined Sobolev inequality which involves the homogeneous Besov norm of negative order, the embedding theorem into HölderZygmund spaces, Trudinger’s inequality for the critical case, the embedding theorem into the BMO or VMO space for the critical case, the trace theorem, the GagliardoNirenberg inequality and its generalization which replaces the \(L^\infty\) norm with the BMO norm or the homogeneous Besov norm, the BrezisGallouetWainger inequality, the BrezisWainger inequality which is related to almost Lipschitz continuity. In this talk I will focus on how to use Muramatu’s integral formula for some of the theorems listed above. Bio: Yoichi Miyazaki was a doctoral student of Professor Tosihusa Kimura at the University of Tokyo, focusing on spectral asymptotics of elliptic operators. He became a research associate at Nihon University in 1988, and received his Ph.D. (Mathematical Sciences) from the University of Tokyo in 1993. He was promoted to an associate professor in 2013, and a professor in 2016.
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Monday, 27 September 2021.
Professor @ Dept. of Mathematics, Postech, Korea.
2021.07 to present: POSTECH, Assistant Professor
2021.05 to 2021.06: KIAS, CMC Fellow
2019.08 to 2021.04 University of Toronto, Postgraduate Fellow
Slides to the talk

Liouville theorem for surfaces translating by subaffinecritical powers of Gauss curvature
We classify the translators to the flows by subaffinecritical powers of Gauss curvature in \(\mathbb{R}^3\). If \(\alpha\) denotes the power, this is a Liouville theorem for degenerate MongeAmpere equations \(\det D^2u = (1+Du^2)^{2\frac{1}{2\alpha}}\) for \(0<\alpha<1/4\). For the affinecriticalcase \(\det D^2u =1\), the classical result by Jorgens, Calabi and Pogorelov shows the level curves of given solution are homothetic ellipses. In our case, the level curves converge asymptotically to a round circle or a curve with \(k\)fold symmetry for some \(k>2\). More precisely, these curves are closed shrinking curves to the \(\frac {\alpha}{1\alpha}\)curve shortening flow that were previously classified by B. Andrews in 2003. This is a joint work with K. Choi and S. Kim.
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Monday, 20 September 2021.
Associate Professor @ University of Sydney.
A/Professor Florica Cirstea graduated with a PhD from Victoria University in April 2005.
From April 2005 to April 2009, she held an ARC Australian Postdoctoral Fellowship (APD).
The teaching (25%) was funded by the Department of Mathematics at the Australian National University and the research (75%) was funded by the Australian Research Council. In July 2008, she transferred her fellowship to the University of Sydney to take up a lectureship position in April 2009. She is an Associate Professor at the University of Sydney since January 2017.
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Anisotropic elliptic equations with gradientdependent lower order terms and \(L^1\) data
Given a bounded open subset \(\Omega\) of \(\mathbb R^N\), we prove the existence of a weak solution for a general class of Dirichlet anisotropic elliptic problems including \(\mathcal Au+\Phi(x,u,\nabla u)=\mathfrak{B}u+f\) in \(\Omega\), where \(f\in L^1(\Omega)\) is arbitrary. The principal part is a divergenceform nonlinear anisotropic operator \(\mathcal A\), the prototype of which is \(\mathcal A u=\sum_{j=1}^N \partial_j(\partial_j u^{p_j2}\partial_j u)\) with \(p_j>1\) for all \(1\leq j\leq N\) and \(\sum_{j=1}^N (1/p_j)>1\). As a novelty, our lower order terms involve a new class of operators \(\mathfrak B\) such that \(\mathcal{A}\mathfrak{B}\) is bounded, coercive and pseudomonotone from \(W_0^{1,\overrightarrow{p}}(\Omega)\) into its dual, as well as a gradientdependent nonlinearity \(\Phi\) with an “anisotropic natural growth" in the gradient and a good sign condition. This talk is based on joint work with Barbara Brandolini (Università degli Studi di Palermo).
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Monday, 13 September 2021.
Professor @ Tohoku University, Japan.
Goro Akagi received a Ph.D from Waseda University in 2004 and his former supervisor is Prof. Mitsuharu Otani. He has been studying evolution equations,
variational problems, nonlinear diffusion equations, AllenCahn and CahnHilliard equations, and so on. He has been a full professor of Mathematical Institute and Graduate School of Science, Tohoku University since Apr 2016.
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Traveling wave dynamics for a onedimensional constrained AllenCahn equation
This talk concerns a onedimensional AllenCahn equation on the whole line with the positivepart function, which constrains the growth of each
solution to be nondecreasing. We shall discuss traveling wave dynamics, which has been well studied for classical AllenCahn equations, for the constrained one. More precisely, we shall start with constructing a oneparameter family of "degenerate" traveling wave solutions (identified when coinciding up to translation) and investigate their properties. Furthermore, the traveling wave dynamics turns out to be relevant to a free boundary problem with a peculiar motion equation for the boundary through an analysis on a regularity issue for the constrained AllenCahn equation, and then, such a viewpoint enables us to prove exponential stability of degenerate traveling waves with some basin of attraction, although they are unstable in a usual sense. This talk is based on a joint work with Christian Kuehn (Muenchen) and KenIchi Nakamura (Kanazawa).
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Monday, 6 September 2021.
Assoc. Professor @ Tokyo Institute of Technology, Japan.
Tatsuya Miura obtained his PhD from the University of Tokyo in 2017. After Postdoctoral Fellow at the Max Planck
Institute for Mathematics in the Sciences around 2018, he was appointed as Assistant Professor in 2019 at the
Tokyo Institute of Technology, where he got promoted to Associate Professor in 2021. He was awarded the MSJ
Takebe Katahiro Prize for Encouragement of Young Researchers in 2017, the JSPS Ikushi Prize in 2018, and
the Inoue Research Award for Young Scientists in 2019.
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LiYau type inequality for curves and applications
A classical result of LiYau asserts an optimal relation between the bending energy (also known as the Willmore energy) and multiplicity of a closed surface in Euclidean space, and is used as a fundamental tool for many studies. In this talk we obtain an analogue for curves in a general form, and observe new phenomena due to low dimensionality. We also discuss its applications to elastic flows, networks, and knots, in particular resolving an open problem posed by Dall'AcquaNovagaPluda.
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Monday, 30 August 2021.
PhD Student @ University of Illinois UrbanaChampaign, United States.
Derek Kielty is a sixthyear Ph.D. student at the University of Illinois UrbanaChampaign advised by Richard Laugesen. Most recently he has worked on various problems related to spectra gaps of the Robin Laplacian and Schrodinger operators.
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Degeneration of the spectral gap with negative Robin parameter.
The spectral gap of the Neumann and Dirichlet Laplacians are each known to have a sharp positive lower bound among convex domains of a given diameter. Between these cases, for each positive value of the Robin parameter an analogous sharp lower bound on the spectral gap is conjectured. In this talk we show the extension of this conjecture to negative Robin parameters fails by proving that the spectral gap of double cone domains are exponentially small, for each fixed parameter value.
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Monday, 26 July 2021.
Professor @ Wuhan University, China.
WeiXi Li is currently a professor at Wuhan University. He received PHD in 2008 from Wuhan University. The research of W.X.Li is microlocal analysis and its application in kinetic and fluid mechanics equations, with special focus on mathematical analysis of boundary layer system and kinetic equations, spectral analysis of FokkerPlanck operator and related models.
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Gevrey wellposedness of the 3D Prandtl equations without Structural Assumption
We establish the wellposedness in Gevrey function space with optimal class of regularity 2 for the three dimensional Prandtl system without any structural assumption. The proof combines in a novel way a new cancellation in the system with some of the old ideas to overcome the difficulty of the loss of derivatives in the system.This shows that the three dimensional instabilities in the system leading to illposedness are not worse than the two dimensional ones. Joint work with Nader Masmoudi and Tong Yang.
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Monday, 19 July 2021.
Professor of Mathematics @ University of Padova, Italy.
Nicola Garofalo is Professor of Mathematics at the University of Padova. He received his Ph.D. in Mathematics from the University of Minnesota in 1987 under the supervision of Eugene Fabes. He has held positions at the University of Bologna, Northwestern University and Purdue University. He has been invited visiting professor at the Institute H. Poincare’, Paris, invited visiting fellow at the I. Newton Institute for Mathematical Sciences, Cambridge, and invited visiting professor at the MittagLeffler Institute, Stockholm. He has also been Distinguished Visiting Professor of Mathematics at the Ohio State University, Visiting Professor of Mathematics at The Johns Hopkins University and Visiting Professor of Mathematics at the University of Maryland. He has received uninterrupted funding from the US National Science Foundation during the years 19892013, and was the recipient of the 2012 Ruth and Joel Spira Award for excellence in graduate teaching.
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A heat equation approach to some problems in conformal geometry.
The Heisenberg group plays an ubiquitous role in analysis, geometry and mathematical physics. Such Lie group is equipped with a natural second order pdo L, the real part of the KohnSpencer sublaplacian, that is hypoelliptic (but fails to be elliptic at every point). It is of interest to study two different families of fractional powers of L, L^s and L_s, and their socalled extension problems. While the former has a purely analytical content, the pseudodifferential operators L_s play a critical role in conformal CR geometry. In this selfcontained talk I plan to show that, notwithstanding their substantial differences, these two classes of nonlocal operators can be treated in a unified way by a systematic use of the heat equation and suitable modifications of the latter. Such approach leads to some intertwining formulas related to conformal geometry that are instrumental in inverting the relevant nonlocal operators, as well as in constructing explicit solutions of some nonlocal Yamabe problems. This is joint work with G. Tralli.
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Monday, 12 July 2021.
Postdoctoral fellow @ Tokyo Metropolitan University, Japan
Toru Nogayama obtained his PhD @ Tokyo Metropolitan University, Japan,
in 2021.
He was a JSPS Research fellow DC @ Tokyo Metropolitan University in 2020.
Since 2021, he is a JSPS Research fellow PD @ Tokyo Metropolitan
University.
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Maximal regularity in BesovMorrey spaces and its application to KellerSegel system
Maximal regularity is an important tool in the theory of
nonlinear differential equations.
Furthermore, from the viewpoint of harmonic analysis, it is also a very
interesting subject.
The maximal regularity for parabolic equations is established within the
general framework on Banach spaces
that satisfy the unconditional martingale differences (called UMD).
Meanwhile, we need to treat differently the maximal regularity
on Banach spaces which do not satisfy UMD. In particular, it is well
known that nonreflexive Banach spaces are not UMD.
In this talk, we discuss the maximal regularity of the heat equation in
BesovMorrey spaces which are not reflexive.
As an application, we present the wellposedness results for the two
dimensional KellerSegel system.
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Monday, 5 July 2021.
Professor @ Politecnico di Milano, Italy.
1999: Researcher at Politecnico di Milano; 2000 PhD in Mathematics at University of Pisa (Advisor G. Buttazzo); 2016today: Full professor at Politecnico di Milano. Main fields of interest: Calculus of variations, shape optimization, PDEs. Author of 80 publications on peerreviewed journals.
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Concavity properties of solutions to Robin problems
We present some recent results about the logconcavity of the Robin ground state and the power concavity of the Robin torsion function on convex domains in the Euclidean Ndimensional space. The results are valid for smooth domains, and for sufficiently large value of the parameter: the threshold for concavity turns out to depend on the space dimension and on the geometry of the domain, precisely on its diameter and boundary curvatures. In particular, this answers positively a conjecture set in 2020 by AndrewsClutterbuckHauer. Anyhow, many related open questions remain open.
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Monday, 28 June 2021.
Professor @ ChungAng University, Seoul, Korea
Professor Hong received his PhD in Mathematics from Brown University, United States, in 2013. After this, he accepted a position as Instructor at the University of Texas at Austin, where he stayed until 2016. From 2016 until February 2018, he was a Postdoctoral researcher at Yonsei University Seoul, South Korea. Since March 2018, Hong is Assistant Professor at ChungAng University in Seoul.
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On the Kortewegde Vries limit for the FermiPastaUlam system
The FermiPastaUlam (FPU) system is a simple nonlinear dynamical lattice model describing a onedimensional chain of vibrating strings with nearest neighbor interactions. This model was introduced by Fermi, Pasta and Ulam in 1955. It was anticipated at that time that chaotic nonlinear interactions would lead to thermalization. Surprisingly however, numerical simulations showed the opposite behavior – it exhibited quasiperiodic motions. This phenomena is known as the FPU paradox. This puzzle has been solved by Zabusky and Kruskal by discovering a formal convergence to the Kortewegde Vries equation, and the convergence has been rigorously justified. We revisit this convergence problem, and show how to put it into the dispersive PDE framework. This talk is based on joint work with Chulkwang Kwak and Changhun Yang.
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Monday, 14 June 2021.
Associate Professor @ Macquarie University, Australia.
Adam Sikora obtained his PhD from the Polish Academy of Science in 1994.
Between 1995 and 2001 he was a visiting fellow at the Australian National University.
Then he worked as Assistant Professor @ New Mexico State University (United States)
before joining Macquarie University in 2009.
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Spreading rate for the FisherKPP nonlocal diffusion equation with free boundary
We consider a class of manifolds \(\mathcal{M}\) obtained by taking the connected
sum of a finite number of \(N\)dimensional Riemannian manifolds of the form
\((\mathbb{R}^{n_i}, \delta) \times (\mathcal{M}_i, g)\), where \(\mathcal{M}_i\)
is a compact manifold, with the product metric. The case of greatest interest is
when the Euclidean dimensions \(n_i\) are not all equal. This means that the ends
have different `asymptotic dimensions', and implies that the Riemannian manifold
\(\mathcal{M}\) is not a doubling space.We completely describe the range of exponents
\(p\) for which the Riesz transform and vertical square function on \(\mathcal{M}\)
are bounded operators on \(L^p(\mathcal{M})\).
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Monday, 31 May 2021.
Professor @ University of New England, Australia.
Yihong obtained his PhD in 1988 from Shandong University (China). After spending two years at Shandong University as a Lecturer (198890),
and one year at HeriotWatt University, UK,(199091), he joined UNE in 1991, as a postdoctoral research fellow (199192) working with Prof. E.N. Dancer.
He became a Lecturer at UNE in 1993 and was promoted to a Professor in 2008. While at UNE, he visited HeriotWatt University (UK), the Chinese Academy
of Science (1999, 2001), the University of Tokyo and Waseda University (2006), and the Institute of Mathematics and Applications at the University of Minnesota (2012).
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Spreading rate for the FisherKPP nonlocal diffusion equation with free boundary
Propagation has been modelled by reactiondiffusion equations since the pioneering works of Fisher and KolmogorovPeterovskiPiskunov (KPP). Much new developments have been achieved in the past several decades on the modelling of propagation, with traveling wave and related solutions playing a central role. In this talk, I will report some recent results obtained with several collaborators on the FisherKPP equation with free boundary and "nonlocal diffusion". A key feature of this nonlocal equation is that the propagation may or may not be determined by traveling wave solutions. There is a threshold condition on the kernel function which determines whether the propagation rate is linear or superlinear in time, also known as accelerated spreading in the latter case, where the rate of spreading is not determined by traveling waves. For some typical kernel functions, sharp estimates of the spreading rate will be presented.
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Monday, 17 May 2021.
Professor @ City University of Hong Kong.
Professor Luo received his PhD from Chinese Academy of Sciences in 1995 under the
supervision of Prof. Ling Hsiao. He held positions at Georgetown University and
University of Michigan before joining the City University of Hong Kong in 2016,
where he is holding a position of professor.
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Estimates and geometry for a free surface problem of fluids with heatconductivity
In this talk, I shall discuss results on the estimates for a free surface problem of highly subsonic heatconducting inviscid flow.
The issues on the loss of derivatives and the coupling of interior solutions and evolving boundary geometry will be addressed.
This talk is based on a joint work with Prof. Huihui Zeng at Tsinghua University.
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Monday, 10 May 2021.
Professor @ Caltech University, United States, and @ Ludwig Maximilian University of Munich, Germany.
He defended his PhD thesis in 2007 @ the Royal Institute of Technology in Stockholm under the supervision of Ari Laptev. After a postdoctoral internship and assistant professorship @ Princeton, in 2013 he became professor @ Caltech and in 2016 at LMU Munich.
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Blowup of solutions of critical elliptic equations in three dimensions
We describe the asymptotic behavior of positive solutions \(u_\varepsilon\) of the equation \[\Delta u + au = 3\,u^{5\varepsilon}\qquad
\textrm{in \(\Omega\subseteq\,\mathbb{R}^3\)}\] with a homogeneous Dirichlet boundary condition. The function \(a\) is assumed to be critical
in the sense of Hebey and Vaugon and the functions \(u_\varepsilon\) are assumed to be an optimizing sequence for the Sobolev
inequality. Under a natural nondegeneracy assumption we derive the exact rate of the blowup and the location of the
concentration point, thereby proving a conjecture of Brézis and Peletier (1989). Similar results are also obtained
for solutions of the equation \[\Delta u + (a+\varepsilon V) u = 3\,u^5\qquad\textrm{ in \(\Omega\).}\] For the variational problem
corresponding to the latter problem we also obtain precise energy asymptotics and a detailed description of the
blowup behavior of almost minimizers (but not necessarily minimizers or solutions).
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Monday, 26 April 2021.
Assistant Professor @ Seoul National University, South Korea.
Professor Jung received his PhD in 2017 from Princeton University, United States,
under the supervision of Professor Yakov Sinai. He became a Research Fellow @ the
Korean Institute of Advanced Study (KIAS) in 2017, where he was promoted to KIAS
Fellow in 2019. Since March 2023, Jung is Assistant Professor @ Seoul National University.
Slides to the talk

Illposedness for incompressible fluid models at critical Sobolev regularity
We consider the incompressible fluid equations including the
Euler and SQG equations in critical Sobolev spaces, which are
Sobolev spaces with the same scaling as the Lipschitz norm of
the velocity. We show that initial value problem for the
equations are illposed at critial regularity.
Such an illposedness result can be used to prove enhanced
dissipation for the dissipative counterpart. The proof
relied on the Key Lemma of Kiselev and Sverak,
which allows to compute the main term of the velocity gradient.
This is based on joint works with Tarek Elgindi, Tsuyoshi
Yoneda, and Junha Kim.
Video of the talk not yet released.

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Monday, 22 February 2021.
Professor @ AixMarseille Université, France
Professor Hamel received his PhD in 1996 @ Sorbonne University
(ExParis VI) under the supervision of Henri Berestycki. Before he
had the privilege to be a student @ the École Normale
Supçrieure de Paris (ENS), later to be a researcher @ CNRS from
1995 until 2001. Since 2001, François Hamel is professor @
AixMarseille Université. He was a Visiting professor @ MIT,
United States and member of the Institut Universitaire de France
from 2009 until 2014.
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Symmetry properties for the Euler equations and semilinear elliptic equations
In this talk, I will discuss radial and onedimensional symmetry
properties for the stationary incompressible Euler equations
in dimension 2 and some related semilinear elliptic equations.
I will show that a steady flow of an ideal incompressible fluid
with no stagnation point and tangential boundary conditions in
an annulus is a circular flow. The same conclusion holds in
complements of disks as well as in punctured disks and in the
punctured plane, with some suitable conditions at infinity or
at the origin. I will also discuss the case of parallel flows
in twodimensional strips, in the halfplane and in the whole
plane.
The proofs are based on the study of the geometric properties
of the streamlines of the flow and on radial and onedimensional
symmetry results for the solutions of some elliptic equations
satisfied by the stream function.
The talk in based on joint work with N. Nadirashvili.
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Professor and Head of the Department of Mathematics and Statistics @ the University of Western Australia.
Serena Dipierro took her PhD in Mathematical Analysis @ the International School for Advanced Studies
(SISSA, Trieste) in 2012. After PostDoc positions @ the Universidad de Chile and University of Edinburgh,
and a Humboldt Fellowship, she held permanent positions @ the University of Melbourne and the Università di Milano.
In August 2018 she moved @ the University of Western Australia, where she is now Professor and Head of the
Department of Mathematics and Statistics.
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Boundary behaviour of nonlocal minimal surfaces
In this talk we present a peculiar behaviour of nonlocal minimal surfaces
(i.e. local minimisers of a nonlocal perimeter functional), namely the capacity, and the strong
tendency, of adhering to the boundary of the reference domain. This characteristic is in contrast
not only with the boundary behaviour of classical minimal surfaces but also with the pattern produced
by solutions of linear equations. We will discuss this phenomenon and present some recent results.
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Monday, 8 March 2021.
Professor @ Tokyo Institute of Technology.
Professor Kagei received his Doctor of Science from Hiroshima University in 1994.
He was research fellow of the Alexander von Humboldt Foundation from 1997 until 1998 @
the University of Bayreuth, Germany. In 1998, Kagei becam Associate Professor @ Kyushu University in Japan,
where he got promoted to Professor in 2006. Since 2019, Kagei is Professor @ the Tokyo Institute of Technology. He
was awarded in 1998 with the prestigeous MSJ Takebe Katahiro Prize of the Mathematical Society of Japan and
in 2012 with the Analysis Prize of the Mathematical Society of Japan.

Stability and bifurcation analysis of the compressible NavierStokes equations
The compressible NavierStokes equation, which is the basic equation for
compressible viscous fluids, is classified as a quasilinear
hyperbolicparabolic system. Due to the hyperbolic and parabolic aspects
of the sysytem, solutions exhbit iinteresting behavior. In this talk, I
will review the stability and bifurcation analysis of the compressible
NavierStokes equation, and state some recent results on a related
bifurcation phenomenon and singular limit problem.
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Monday, 15 February 2021.
Professor @ Wuhan University, China.
Professor Miao received his PhD in July 2013 @ the University of Chinese Academy of Sciences
under the supervision of Prof. Demetrios Christodoulou and Prof. Ping Zhang. Before he accepted the
professorship @ Wuhan University, he held several postdoc positions @ University of Michigan, @ ETH Zurich,
and @ EPFL in Switzland.
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On the free boundary hard phase fluid in Minkowski spacetime
I will present a recent work on the free boundary hard phase fluid model with Minkowski background.
The hard phase model is an idealized model for a relativistic fluid where the sound speed approaches
the speed of light. This work consists of two results: First, we prove the wellposedness of this model
in Sobolev spaces. Second, we give a rigorous justification of the nonrelativistic limit for this model
as the speed of light approaches infinity.
This is joint work with Sohrab Shahshahani and Sijue Wu.
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Monday, 22 March 2021.
Postdoctoral Fellow @ University of British Columbia, Canada.
Palmer received his PhD in mathematics @ Cornell University in 2016 under the supervision of Tim Healey
on a topic of nonlinear elasticity. Currently, he is working as a postdoctoral fellow @ the University of British Columbia jointly
with Nassif Ghoussoub and YoungHeon Kim on topics related to optimal transport.
Slides to the talk

Hidden Convexity in problem of Nonlinear Elasticity
Problems in elasticity / solid mechanics have been essential to the development of the theory of partial differential equations
and Calculus of Variations. However, fundamental questions regarding the regularity of equilibria in nonlinear elasticity remain
largely unanswered. The theory of optimal transport has had a lot of recent success in the analysis of nonlinear PDE, ranging
from the MongeAmpere equation to kinetic gas equations.
In a recent work, we introduced techniques from optimal transport to problems of nonlinear elasticity and uncover a hidden convexity.
I will discuss the connection between optimal transport and nonlinear elasticity, and our results on when equilibria in nonlinear
elasticity correspond to minimizers of an optimal transport problem.
This is joint work with Nassif Ghoussoub and Hugo Lavenant.
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Monday, 25 January 2021.
Professor @ Nagoya University, Japan
Professor Sugimoto was a Research Associate @ University of Tsukuba in 198790 and received his Ph.D. there in 1992. He worked @ Osaka University from 1990 until 2008, and is now a Professor @ Nagoya University since 2008.
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A constructive approach to semilinear wave equations
In this talk, I will explain a new attempt to construct selfsimilar solutions to semilinear wave equations with power nonlinearity. The existence of selfsimilar solutions to the same equations has been already established by Pecher (2000), KatoOzawa (2003), etc. based on the standard fixed point theorem. We will rediscuss it by a constructive approach using the theory of hypergeometric differential equations.
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Monday, 8 February 2021.
Head of the Laboratoire JacquesLouis Lions and Professor @ Sarbonne Université,
CNRS, Université de Paris, France
Emmanuel Trélat got his PhD in 2000 in optimal control
and subRiemannian geometry, under the supervision of Bernard
Bonnard, at Dijon University, France. He became an assistant
professor at ParisSud University (Orsay) in 2001, then professor at
Orléans University in 2006, and he moved to Pierre
et Marie Curie University (now named Sorbonne University) at Paris in 2011.
He is the head of Laboratoire JacquesLouis Lions.
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Spectral analysis of subRiemannian Laplacians and Weyl measure
In collaboraton with Yves Colin de Verdière and Luc Hillairet,
we study spectral properties of subRiemannian Laplacians, which
are selfadjoint hypoelliptic operators satisfying the
Hörmander condition.
Thanks to the knowledge of the smalltime asymptotics of heat
kernels in a neighborhood of the diagonal, we establish the
local and microlocal Weyl law.
When the Lie bracket configuration is regular enough (equiregular case),
the Weyl law resembles that of the Riemannian case. But in the
singular case (e.g., BaouendiGrushin, MarVnet) the Wey law reveals
much more complexity. In turn, we derive quantum ergodicity
properties in some subRiemannian cases.
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Monday, 15 March 2021.
Professor @ the Beijing Institute of Technology.
Rongchan Zhu got her Phd in 2021 @ Chinese Academy of Science and Bielefeld University. Now, she is professor @ the Beijing Institute of Technology.
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Large \(N\) Limit of the \(O(N)\) Linear Sigma Model via Stochastic Quantization
In this talk, I will discuss large \(N\) limits of a coupled system of \(N\) interacting \(\Phi^4\) equations posed over \(\mathbb{T}^{d}\) for \(d=1,2,3\),
known as the \(O(N)\) linear sigma model. Uniform in \(N\) bounds on the dynamics are established, allowing us to show convergence to a meanfield singular
SPDE, also proved to be globally wellposed. Moreover, I show tightness of the invariant measures in the large \(N\) limit. For large enough mass, they
converge to the (massive) Gaussian free field, the unique invariant measure of the meanfield dynamics, at a rate of order \(1/\sqrt{N}\) with respect to
the Wasserstein distance.
I will also consider fluctuations and obtain tightness results for certain \(O(N)\) invariant observables, along with an exact description of the limiting
correlations in \(d=1,2\).
This talk is based on joint work with Hao Shen, Scott Smith and Xiangchan Zhu.
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