# MBZ~i[

ꏊ: MBww A4K ER񍇓 (401)
bl: I. Trushin, J, {gv

## 2021Nx

🆕 6 2021N 12 16() 16:30-
F̃Z~i[̓ICŊJÂ܂D
u: ɓ (w)
: Pseudodifferential expression for the S-matrix of perturbed Stark Hamiltonian

## ȑO̍u

5 2019N 6 7() 16:30-18:00
u: J BY (w _)
: Weakly hyperbolic systems by symmetrization
Tv: V{ŗLl݂̂1K̔nɑ΂āC̏l Gevrey ̂NXœK؂ƂȂ(M.Bronshtein). ̍uł́C[pfp symmetrizer \邱ƂɂGlM[s𓱂CV{̃XyNg\l̓K؃NXɔfł̌ʂ. Symmetrizer ̍\͏_ɂ Lyapunov ֐̍\ɕ키. ̕@ɂƎV{̃XyNg\fꂽGlM[seՂɂRɓƂł. ܂ spectral truncations ɑ΂l]eՂɓ ŏЉ錋ʂ F.Colombini (Pisa), J.Rauch (Michigan) Ƃ̋ɊÂ.

4 2018N 12 17() 16:30 - 18:00
u: ߌ TV (cw)
: Well-posedness and ill-posedness of the stationary Navier-Stokes equations in the scaling invariant Besov space
Tv: 񈳏kNavier-Stokes̃XP[sςBesovԂɂKؐ i^ꂽO͂ɘAIɈˑ̈ӑݐjєKؐɂčl@. {uł͓ɔKؐɏœ_𓖂, O͂̋Ԃ̈ʑ߂ ̘Aˑꍇ邱Ƃؖ. { Cunanan-Okabe-Tsutsui (2017) Kaneko-Kozono-Shimizu (2017) ɂKؐɊւsʂ, BesovԂ̘gg݂ŊTˍœKł邱Ƃ̂ł.

3 2017N 2 20() 16:30 - 18:00
u: v (kw)
: Asymptotic expansions of solutions of fractional diffusion equations
Tv: We obtain the precise description of the asymptotic behavior of the solution $u$ of $\partial_t u + (- \Delta)^{\theta/2}u = 0$ in ${\bf R}^N \times(0,\infty),\ u(x,0)=\varphi(x)$ in ${\bf R}^N$, where $0 < \theta < 2$ and $\varphi \in L_K:=L^1({\bf R}^N,\ (1+|x|)^K dx)$ with $K \ge 0$. Furthermore, we develop the arguments in Ishige-Kawakami (2012) and Ishige-Kawakami-Kobayashi (2014) and establish a method to obtain the asymptotic expansions of the solutions to a nonlinear fractional diffusion equation $\partial_t u+(-\Delta)^{\theta/2}u=|u|^{p-1}u$ in ${\bf R}^N \times(0,\infty)$, where $0 < \theta < 2$ and $p > 1 + \theta/N$. Joint work with Kazuhiro Ishige and Tatsuki Kawakami.

2 2016N 12 9 () 16:30-18:00
u: FM (sw)
: The Wolff potential estimate for solutions to elliptic equations with signed data
Tv: $p$-Da֐ɑ΂ Wolff |eVɂe_]ɂčl. ̕], $p$-a֐ Wiener ̔̕Kv̂ Kilpel{\"a}inen-Mal{\'y} (1994) ɂēꂽ. Trudinger-Wang (2002) ͂̕] Poisson ό𗘗pVؖ^. Duzaar-Mingione (2010) ͌z]̐V@p, $p \geq 2$ ̏ꍇɕtO͂ɑ΂ɑ΂Ăގ̊e_]^. {uł, Poisson ό` Kilpel{\"a}inen-Mal{\'y} ̎@gݍ킹邱Ƃ, 2̕] $1 < p < 2$ tO͂̏ꍇ܂߂Vؖ^.

1 2016N 11 11 () 16:30-18:00
u: Chris Jeavons (cw)
: On sharp linear and bilinear Strichartz inequalities
Tv: In recent years the problem of determining best constants and the shape of maximisers for well-known functional inequalities has attracted considerable attention, but has proved difficult in general. In my talk I will present some progress on this problem for the classical Strichartz inequalities for the wave and Klein--Gordon equations. In each case, our proof combines a bilinear estimate with techniques developed recently in the study of closely-related Fourier restriction inequalities. The bilinear estimates we prove are interesting in their own right; if time permits I will discuss some further applications of these results.
The talk will be based on a number of joint works with Neal Bez, Hiroki Saito and Tohru Ozawa

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