FMSP Lectures

Seminar information archive ~04/19Next seminarFuture seminars 04/20~


Seminar information archive

2016/11/04

10:30-11:30   Room #128 (Graduate School of Math. Sci. Bldg.)
Piotr Rybka (the University of Warsaw)
The BV space in variational and evolution problems (3) (ENGLISH)
[ Abstract ]
https://www.ms.u-tokyo.ac.jp/kyoumu/docs/20160907.pdf を参照
[ Reference URL ]
http://fmsp.ms.u-tokyo.ac.jp/FMSPLectures_Rybka.pdf

2016/11/04

13:00-14:00   Room #128 (Graduate School of Math. Sci. Bldg.)
Piotr Rybka (the University of Warsaw)
The BV space in variational and evolution problems (4) (ENGLISH)
[ Abstract ]
https://www.ms.u-tokyo.ac.jp/kyoumu/docs/20160907.pdf を参照
[ Reference URL ]
http://fmsp.ms.u-tokyo.ac.jp/FMSPLectures_Rybka.pdf

2016/11/01

10:30-11:30   Room #128 (Graduate School of Math. Sci. Bldg.)
Piotr Rybka (the University of Warsaw)
The BV space in variational and evolution problems (1) (ENGLISH)
[ Abstract ]
https://www.ms.u-tokyo.ac.jp/kyoumu/docs/20160907.pdf を参照
[ Reference URL ]
http://fmsp.ms.u-tokyo.ac.jp/FMSPLectures_Rybka.pdf

2016/11/01

13:15-14:15   Room #128 (Graduate School of Math. Sci. Bldg.)
Piotr Rybka (the University of Warsaw)
The BV space in variational and evolution problems (2) (ENGLISH)
[ Abstract ]
https://www.ms.u-tokyo.ac.jp/kyoumu/docs/20160907.pdf を参照
[ Reference URL ]
http://fmsp.ms.u-tokyo.ac.jp/FMSPLectures_Rybka.pdf

2016/09/26

16:00-17:30   Room #056 (Graduate School of Math. Sci. Bldg.)
Murray Muraskin (University of North Dakota, Grand Forks)
Mathematical Aesthetic Principles and Nonintegrable Systems (ENGLISH)
[ Abstract ]
The discussion presents a study of a set of mathematical principles that can be classified as "aesthetic”and shows that these principles can be cast into a set of nonlinear equations. The system of equations is nonintegrable in general. New techniques to handle the nonintegrability feature are discussed. We then illustrate how this system of equations leads to sinusoidal solutions, sine within sine solutions, the phenomenon known as beats, random type oscillations, two and three dimensional lattices, as well as multi wave packet systems. The sinusoidal solutions occur when the arbitrary data associated with the equations causes the equations to be linearized. The sinusoidal behavior totally disappears once the integrability equations are satisfied, illustrating how important the nonintegrability concept is to the development.
[ Reference URL ]
http://fmsp.ms.u-tokyo.ac.jp/FMSPLectures_Muraskin.pdf

2016/08/12

15:00-16:00   Room #128 (Graduate School of Math. Sci. Bldg.)
Eric Chung (Chinese Univ. of Hong Kong)
Multiscale simulations of waves and applications (ENGLISH)
[ Abstract ]
Numerical simulations of wave propagation in heterogeneous media are important in many applications such as seismic propagation and seismic inversion.
In this talk, we will present a new multiscale approach for seismic wave propagation.
The method is able to compute the solution with much fewer degrees of freedom compared with fine mesh simulation.
The idea is to capture the multiscale features of the solutions by carefully designed multiscale basis functions.
We will also present applications to inverse problems.
[ Reference URL ]
http://fmsp.ms.u-tokyo.ac.jp/FMSPLectures_Chung.pdf

2016/08/12

16:00-17:00   Room #128 (Graduate School of Math. Sci. Bldg.)
Christian Clason (University Duisburg-Essen)
Discrete regularization of parameter identification problems (ENGLISH)
[ Abstract ]
This talk is concerned with parameter identification problems where a distributed parameter is known a priori to take on values from a given set. This property can be promoted with the aid of a convex regularization term in the Tikhonov functional. We discuss the properties of minimizers of this functional and their numerical computation using a semismooth Newton method.
[ Reference URL ]
http://fmsp.ms.u-tokyo.ac.jp/FMSPLectures_Clason.pdf

2016/08/10

10:00-11:00   Room #370 (Graduate School of Math. Sci. Bldg.)
Benny Y C Hon (City Univ. of Hong Kong)
Global-local-integration-based kernel approximation methods: Technical arguments (ENGLISH)
[ Abstract ]
We discuss technical details of my talk on 8 Aug. and give also proofs of some main results.
[ Reference URL ]
http://fmsp.ms.u-tokyo.ac.jp/FMSPLectures_Hon2.pdf

2016/08/08

16:30-17:30   Room #128 (Graduate School of Math. Sci. Bldg.)
Benny Y C Hon (City Univ. of Hong Kong)
Global-local-integration-based kernel approximation methods (ENGLISH)
[ Reference URL ]
http://fmsp.ms.u-tokyo.ac.jp/FMSPLectures_Hon.pdf

2016/08/08

17:30-18:30   Room #128 (Graduate School of Math. Sci. Bldg.)
Daniel Gerth (Tech. Univ. Chemnitz)
On the lifting of deterministic convergence results for inverse problems to the stochastic setting (ENGLISH)
[ Abstract ]
In inverse problems, the inevitable measurement noise is modelled either by a deterministic worst-case model or a stochastic one.
The development of convergence theory in both approaches appears to be rather disconnected. In this talk we seek to bridge this gap and show how deterministic result can be transferred into the stochastic setting. The talk is split into two parts. In the first part, after briefly introducing "inverse problems" and the noise models, we examine the particular problem of sparsity-promoting regularization with a Besov-space penalty term to demonstrate the lifting technique. In the second part, we present a generalization of the technique that applies to a large group of regularization methods.
[ Reference URL ]
http://fmsp.ms.u-tokyo.ac.jp/FMSPLectures_Gerth.pdf

2016/06/23

15:00-16:30   Room #056 (Graduate School of Math. Sci. Bldg.)
Klaus Mainzer (Technische Universität München)
Complexity and Computability: Complex Dynamical Systems beyond Turing-Computability (ENGLISH)
[ Abstract ]
The computational theory of complexity is founded by digital computing (e.g. Turing machine) which cannot fully grasp continuous concepts of mathematics. The mathematical theory of complex dynamical systems (with interdisciplinary applications in natural and economic sciences) is based on continuous concepts. Further on, there is an outstanding tradition in mathematics since Newton, Leibniz, Euler et al. with real algorithms in, e.g., numerical analysis. How can the gap between the digital and continuous world be mathematically overcome? The talk aims at mathematical and philosophical foundations and interdisciplinary applications of complex dynamical systems beyond Turing-computability.
[ Reference URL ]
http://fmsp.ms.u-tokyo.ac.jp/FMSPLectures_Mainzer.pdf

2016/05/09

15:00-17:00   Room #002 (Graduate School of Math. Sci. Bldg.)
Michael Tuite (National University of Ireland, Galway)
Vertex Operator Algebras according to Newton (ENGLISH)
[ Abstract ]
In this lecture I will give an introduction to Vertex Operator Algebras (VOAs) using elementary methods originally due to Isaac Newton. I will also discuss a class of exceptional VOAs including the Moonshine module which share a number of fundamental properties in common.
[ Reference URL ]
http://fmsp.ms.u-tokyo.ac.jp/FMSPLectures_Tuite.pdf

2016/04/21

15:00-16:00, 16:10-17:10   Room #002 (Graduate School of Math. Sci. Bldg.)
Aniceto Murillo et al (Universidad de Malaga)
Rational homotopy theory : Quillen and Sullivan approach.(2) (ENGLISH)
[ Reference URL ]
http://fmsp.ms.u-tokyo.ac.jp/FMSPLectures_Murillo.pdf

2016/04/20

15:00-16:00, 16:10-17:10   Room #002 (Graduate School of Math. Sci. Bldg.)
Aniceto Murillo et al (Universidad de Malaga)
Rational homotopy theory : Quillen and Sullivan approach.(1) (ENGLISH)
[ Reference URL ]
http://fmsp.ms.u-tokyo.ac.jp/FMSPLectures_Murillo.pdf

2016/04/14

15:30-17:00   Room #Lecture Hall, Kavli IPMU (Graduate School of Math. Sci. Bldg.)
Alan Weinstein (University of California, Berkeley)
Lecture 2: Geometric and algebraic Poisson modules (ENGLISH)
[ Reference URL ]
http://fmsp.ms.u-tokyo.ac.jp/FMSPLectures_Weinstein.pdf

2016/04/13

13:30-14:30   Room #126 (Graduate School of Math. Sci. Bldg.)
Yavar Kian (Aix-Marseille Univ.)
Determination of time-dependent coefficients for wave equations from partial data (ENGLISH)
[ Reference URL ]
http://fmsp.ms.u-tokyo.ac.jp/FMSPLectures_Kian.pdf

2016/04/11

15:30-17:00   Room #Lecture Hall, Kavli IPMU (Graduate School of Math. Sci. Bldg.)
Alan Weinstein (University of California, Berkeley)
Lecture 1: Special subspaces in symplectic vector spaces (ENGLISH)
[ Reference URL ]
http://fmsp.ms.u-tokyo.ac.jp/FMSPLectures_Weinstein.pdf

2016/03/22

10:00-11:00   Room #118 (Graduate School of Math. Sci. Bldg.)
Fatiha Alabau (Université de Lorraine)
Control and stabilization of degenerate wave equations (ENGLISH)
[ Abstract ]
The control of degenerate PDE's arise in many applications such as cloaking, climatology, population genetics, and vision.
For such models, the diffusion operator degenerates on some subset of the spatial domain. We present some recent results on observability, control and stabilization of these equations.
This is a joint work with Piermarco Cannarsa (University di Roma Tor Vergata, Italy) and G\"unter Leugering (Friedrich-Alexander-Universit\"at Erlangen-N\"urnberg, Erlangen, Germany).
[ Reference URL ]
http://fmsp.ms.u-tokyo.ac.jp/FMSPLectures_Alabau.pdf

2016/03/22

11:00-12:00   Room #118 (Graduate School of Math. Sci. Bldg.)
Mourad Bellassoued (Université de Tunis El Manar)
Stable determination of coefficients in the dynamical Schrödinger equation in a magnetic field (ENGLISH)
[ Reference URL ]
http://fmsp.ms.u-tokyo.ac.jp/FMSPLectures_Bellassoued.pdf

2016/03/19

11:00-12:00   Room #370 (Graduate School of Math. Sci. Bldg.)
Oleg Emanouilov (Colorado State Univ.)
About the Landis conjecture (ENGLISH)
[ Reference URL ]
http://fmsp.ms.u-tokyo.ac.jp/FMSPLectures_Emanouilov160319.pdf

2016/03/18

14:30-15:30   Room #118 (Graduate School of Math. Sci. Bldg.)
Piermarco Cannarsa (Università degli Studi di Roma Tor Vergata)
Control of degenerate parabolic equations: old and new (ENGLISH)
[ Abstract ]
This talk will survey the main results obtained in the last fifteen years or so for the null controllability of degenerate parabolic operators.
We shall describe the state of the art for operators which degenerate at the boundary as well as for certain classes of interior degeneracy of hypoelliptic type.
[ Reference URL ]
http://fmsp.ms.u-tokyo.ac.jp/FMSPLectures_Cannarsa.pdf

2016/02/22

17:00-18:00   Room #118 (Graduate School of Math. Sci. Bldg.)
Michel Cristofol (Aix-Marseille Univ.)
Inverse problems for parabolic operators : comparison of three different approaches (ENGLISH)
[ Abstract ]
Basing my talk around a toy problem : reconstruction of the potential for a linear parabolic problem, I will recall the two main classical following methods : Dirichlet to Neumann map and Carleman estimates. Then I will present a different and recent approach based on pointwise observations and I will underline some points to be improved for each method. Then, I will finish my talk by a review of some results related to this technic of pointwise observations.
[ Reference URL ]
http://fmsp.ms.u-tokyo.ac.jp/FMSPLectures_Cristofol.pdf

2016/02/19

10:30-11:30   Room #118 (Graduate School of Math. Sci. Bldg.)
Olivier Poisson (Aix-Marseille University)
Recovering time-dependent inclusion in heat conductive bodies by a dynamical probe method (ENGLISH)
[ Abstract ]
Many articles solve a version of the Calder'on inverse problem for the heat equation. The biggest part of them assume that the unknown conductivity do not depend on time t. But they are very few results concerning the time de- pendent situation, and they are based on the computation of an ansatz for the parabolic equation:
- A reconstruction method of an unknown moving inclusion by a dynamical probe method was performed by Daido-Kang-Nakamura in 2007, but it works for the one dimensional spatial space only,
- An energy estimate for x-multidimensional convex inclusions.
In the talk I will present a dynamical probe method based on special fundamental solutions of the heat equation and basic inequalities :
this approach is very close to the probe method for the elliptic Calderon inverse problem, and does not require regularity of the inclusion.
[ Reference URL ]
http://fmsp.ms.u-tokyo.ac.jp/FMSPLectures_Poisson.pdf

2016/02/18

10:00-11:00   Room #002 (Graduate School of Math. Sci. Bldg.)
Dror Varolin (Stony Brook)
L^2 Extension and its applications: A survey (3) (ENGLISH)
[ Abstract ]
We discuss certain aspects of the theory of L^2 extension, going back to the famous and fundamental work of Ohsawa and Takegoshi, and even further back to work of Donnelly and Fefferman.
The first of three lectures will recall a number of L^2 extension theorems, to some extent following an incomplete history (as I see it), and ending with a sketch of a proof of one of these theorems.
The second lecture will discuss a number of my favorite applications of L^2 extension, from Bergman kernels to deformation invariance of plurigenera.
The third lecture will discuss a new proof of the extension theorem, due to Berndtsson and Lempert. The key tool is a theorem of Berndtsson on the positivity of direct images, which we will review. Berndtsson's theorem permits the introduction of degeneration techniques, whose surprising application to L^2 extension represents one of the most beautiful and fundamental recent breakthroughs in the subject.
[ Reference URL ]
http://fmsp.ms.u-tokyo.ac.jp/FMSPLectures_Varolin.pdf

2016/02/18

10:30-11:30   Room #118 (Graduate School of Math. Sci. Bldg.)
Michel Cristofol (Aix-Marseille Univ.)
Inverse boundary value problem for a hyperbolic equation in an infinite guide (ENGLISH)
[ Abstract ]
We consider the multidimensional inverse problem of determining the conductivity coefficient of a hyperbolic equation in an infinite cylindrical domain, from a single boundary observation of the solution. We prove Holder stability with the aid of a Carleman estimate specially designed for hyperbolic waveguides. I will provide numerical simulations in multiple backgrounds.
[ Reference URL ]
http://fmsp.ms.u-tokyo.ac.jp/FMSPLectures_Cristofol.pdf

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