Seminar information archive
Seminar information archive ~09/14|Today's seminar 09/15 | Future seminars 09/16~
thesis presentations
13:00-14:15 Room #128 (Graduate School of Math. Sci. Bldg.)
Hisashi KASUYA (Guraduate School of Mathematical Sciences the University of Tokyo)
Topology, symplectic geometry and complex geometry of solvmanifolds -From nilpotent to solvable- (JAPANESE)
Hisashi KASUYA (Guraduate School of Mathematical Sciences the University of Tokyo)
Topology, symplectic geometry and complex geometry of solvmanifolds -From nilpotent to solvable- (JAPANESE)
thesis presentations
14:15-15:30 Room #128 (Graduate School of Math. Sci. Bldg.)
Keisuke MATSUYA (Guraduate School of Mathematical Sciences the University of Tokyo)
Discretization and ultradiscretization of differential equations preserving characters of their solutions (JAPANESE)
Keisuke MATSUYA (Guraduate School of Mathematical Sciences the University of Tokyo)
Discretization and ultradiscretization of differential equations preserving characters of their solutions (JAPANESE)
2013/02/07
Operator Algebra Seminars
16:30-18:00 Room #002 (Graduate School of Math. Sci. Bldg.)
David Kerr (東大数理/Texas A&M Univ.)
Combinatorial independence, amenability, and sofic entropy (ENGLISH)
David Kerr (東大数理/Texas A&M Univ.)
Combinatorial independence, amenability, and sofic entropy (ENGLISH)
thesis presentations
09:45-11:00 Room #118 (Graduate School of Math. Sci. Bldg.)
Naoki KATO (Guraduate School of Mathematical Sciences the University of Tokyo)
Lie foliations transversely modeled on nilpotent Lie algebras
(JAPANESE)
Naoki KATO (Guraduate School of Mathematical Sciences the University of Tokyo)
Lie foliations transversely modeled on nilpotent Lie algebras
(JAPANESE)
thesis presentations
11:00-12:15 Room #118 (Graduate School of Math. Sci. Bldg.)
Toshikazu KUNIYA (Guradate School of Mathematical Sciences the University of Tokyo)
Mathematical Analysis for Epidemic Models with Heterogeneity (JAPANESE)
Toshikazu KUNIYA (Guradate School of Mathematical Sciences the University of Tokyo)
Mathematical Analysis for Epidemic Models with Heterogeneity (JAPANESE)
thesis presentations
13:00-14:15 Room #118 (Graduate School of Math. Sci. Bldg.)
Kazuaki MIYATANI (Guraduate School of Mathematical Sciences the University of Tokyo)
MONOMIAL DEFORMATIONS OF CERTAIN HYPERSURFACES AND TWO HYPERGEOMETRIC FUNCTIONS
(JAPANESE)
Kazuaki MIYATANI (Guraduate School of Mathematical Sciences the University of Tokyo)
MONOMIAL DEFORMATIONS OF CERTAIN HYPERSURFACES AND TWO HYPERGEOMETRIC FUNCTIONS
(JAPANESE)
thesis presentations
14:15-15:30 Room #118 (Graduate School of Math. Sci. Bldg.)
Takayuki OKUDA (Guraduate School of Mathematical Sciences the University of Tokyo)
Proper actions and designs on homogeneous spaces (JAPANESE)
Takayuki OKUDA (Guraduate School of Mathematical Sciences the University of Tokyo)
Proper actions and designs on homogeneous spaces (JAPANESE)
thesis presentations
15:45-17:00 Room #118 (Graduate School of Math. Sci. Bldg.)
Kenichi KONDO (Guraduate School of Mathematical Sciences the University of Tokyo)
Symmetrized Max-Plus Algebra and Ultradiscrete sine-Gordon Equation (JAPANESE)
Kenichi KONDO (Guraduate School of Mathematical Sciences the University of Tokyo)
Symmetrized Max-Plus Algebra and Ultradiscrete sine-Gordon Equation (JAPANESE)
thesis presentations
09:45-11:00 Room #128 (Graduate School of Math. Sci. Bldg.)
Tomoyuki HISAMOTO (Guraduate School of Mathematical Sciences the University of Tokyo)
Asymptotic analysis of Bergman kernels for linear series and its application to Kahler Geometry (JAPANESE)
Tomoyuki HISAMOTO (Guraduate School of Mathematical Sciences the University of Tokyo)
Asymptotic analysis of Bergman kernels for linear series and its application to Kahler Geometry (JAPANESE)
thesis presentations
11:00-12:15 Room #128 (Graduate School of Math. Sci. Bldg.)
Yoshihiko MATSUMOTO (Guraduate School of Mathematical Sciences the University of Tokyo)
Asymptotically complex hyperbolic Einstein metrics and CR geometry (JAPANESE)
Yoshihiko MATSUMOTO (Guraduate School of Mathematical Sciences the University of Tokyo)
Asymptotically complex hyperbolic Einstein metrics and CR geometry (JAPANESE)
thesis presentations
13:00-14:15 Room #128 (Graduate School of Math. Sci. Bldg.)
Tomoro ASAI (Guraduate School of Mathematical Sciences the University of Tokyo)
Analytic semigroup approach to higher order quasilinear parabolic problems (JAPANESE)
Tomoro ASAI (Guraduate School of Mathematical Sciences the University of Tokyo)
Analytic semigroup approach to higher order quasilinear parabolic problems (JAPANESE)
thesis presentations
14:15-15:30 Room #128 (Graduate School of Math. Sci. Bldg.)
Makoto MIURA (Guraduate School of Mathematical Sciences the University of Tokyo)
Hibi toric varieties and mirror symmetry (JAPANESE)
Makoto MIURA (Guraduate School of Mathematical Sciences the University of Tokyo)
Hibi toric varieties and mirror symmetry (JAPANESE)
thesis presentations
15:45-17:00 Room #128 (Graduate School of Math. Sci. Bldg.)
Tomohiko ISHIDA (Guraduate School of Mathematical Sciences the University of Tokyo)
Quasi-morphisms on the group of area-preserving diffeomorphisms of the 2-disk (JAPANESE)
Tomohiko ISHIDA (Guraduate School of Mathematical Sciences the University of Tokyo)
Quasi-morphisms on the group of area-preserving diffeomorphisms of the 2-disk (JAPANESE)
GCOE Seminars
17:00-18:30 Room #370 (Graduate School of Math. Sci. Bldg.)
Asaf Iskandarov (Lenkaran State University)
Identification of quantum potentials in the Schrodinger equation (ENGLISH)
Asaf Iskandarov (Lenkaran State University)
Identification of quantum potentials in the Schrodinger equation (ENGLISH)
[ Abstract ]
In this lecture I will consider the identification problem of determining the unknown time-dependent coefficients of nonlinear Schrodinger equation.We applied the variational method and studied the correctness of direct and identification problems. We find a necessary condition of the solution and give a stable methed for solution.
In this lecture I will consider the identification problem of determining the unknown time-dependent coefficients of nonlinear Schrodinger equation.We applied the variational method and studied the correctness of direct and identification problems. We find a necessary condition of the solution and give a stable methed for solution.
Seminar on Probability and Statistics
11:00-12:10 Room #006 (Graduate School of Math. Sci. Bldg.)
Stefano M. Iacus (Dipartimento di Economia, Managemente Metodi Quantitativi Universita' di Milano)
On L^p model selection for discretely observed diffusion processes (JAPANESE)
http://www.sigmath.es.osaka-u.ac.jp/~kamatani/statseminar/2012/14.html
Stefano M. Iacus (Dipartimento di Economia, Managemente Metodi Quantitativi Universita' di Milano)
On L^p model selection for discretely observed diffusion processes (JAPANESE)
[ Abstract ]
The LASSO is a widely used L^2 statistical methodology for simultaneous estimation and variable selection. In the last years, many authors analyzed this technique from a theoretical and applied point of view. In the first part of the seminar, we introduce and study the adaptive LASSO problem for discretely observed ergodic diffusion processes We prove oracle properties also deriving the asymptotic distribution of the LASSO estimator. In the second part of the seminar we present general L^p approach for stochastic differential equations with small diffusion noise. Finally, we present simulated and real data analysis to provide some evidence on the applicability of this method.
FMSP Lectures
http://faculty.ms.u-tokyo.ac.jp/~fmsp/jpn/conferences/fmsp.html
[ Reference URL ]The LASSO is a widely used L^2 statistical methodology for simultaneous estimation and variable selection. In the last years, many authors analyzed this technique from a theoretical and applied point of view. In the first part of the seminar, we introduce and study the adaptive LASSO problem for discretely observed ergodic diffusion processes We prove oracle properties also deriving the asymptotic distribution of the LASSO estimator. In the second part of the seminar we present general L^p approach for stochastic differential equations with small diffusion noise. Finally, we present simulated and real data analysis to provide some evidence on the applicability of this method.
FMSP Lectures
http://faculty.ms.u-tokyo.ac.jp/~fmsp/jpn/conferences/fmsp.html
http://www.sigmath.es.osaka-u.ac.jp/~kamatani/statseminar/2012/14.html
2013/02/05
Lie Groups and Representation Theory
17:30-19:00 Room #126 (Graduate School of Math. Sci. Bldg.)
Nizar Demni (Université de Rennes 1)
Dunkl processes assciated with dihedral systems, II (ENGLISH)
Nizar Demni (Université de Rennes 1)
Dunkl processes assciated with dihedral systems, II (ENGLISH)
[ Abstract ]
I'll focus on dihedral systems and its semi group density. I'll show how one can write down this density using probabilistic techniques and give some interpretation using spherical harmonics. I'll also present some results attempting to get a close formula for the density: the main difficulty comes then from the inversion (in composition sense) of Tchebycheff polynomials of the first kind in some neighborhood. Finally, I'll display expressions through known special functions for even dihedral groups, and the unexplained connection between the obtained formulas and those of Ben Said-Kobayashi-Orsted.
I'll focus on dihedral systems and its semi group density. I'll show how one can write down this density using probabilistic techniques and give some interpretation using spherical harmonics. I'll also present some results attempting to get a close formula for the density: the main difficulty comes then from the inversion (in composition sense) of Tchebycheff polynomials of the first kind in some neighborhood. Finally, I'll display expressions through known special functions for even dihedral groups, and the unexplained connection between the obtained formulas and those of Ben Said-Kobayashi-Orsted.
2013/02/04
Lie Groups and Representation Theory
17:30-19:00 Room #126 (Graduate School of Math. Sci. Bldg.)
Nizar Demni (Université de Rennes 1)
Dunkl processes assciated with dihedral systems, I (ENGLISH)
Nizar Demni (Université de Rennes 1)
Dunkl processes assciated with dihedral systems, I (ENGLISH)
[ Abstract ]
I'll first give a brief and needed account on root systems and finite reflection groups. Then, I'll introduce Dunkl operators and give some properties. Once I'll do, I'll introduce Dunkl processes and their continuous components, so-called radial Dunkl processes. The latter generalize eigenvalues processes of some matrix-valued processes and reduces to reflected Brownian motion in Weyl chambers. Besides, Brownian motion in Weyl chambers corresponds to all multiplicity values equal one are constructed from a Brownian motion killed when it first hits the boundary of the Weyl chamber using the unique positive harmonic function (up to a constant) on the Weyl chamber. In the analytic side, determinantal formulas appear and are related to harmonic analysis on the Gelfand pair (Gl(n,C), U(n)). This is in agreement on the one side with the so-called reflection principle in stochastic processes theory and matches on the other side the so-called shift principle introduced by E. Opdam. Finally, I'll discuss the spectacular result of Biane-Bougerol-O'connell yielding to a Duistermaat-Heckman distribution for non crystallographic systems.
I'll first give a brief and needed account on root systems and finite reflection groups. Then, I'll introduce Dunkl operators and give some properties. Once I'll do, I'll introduce Dunkl processes and their continuous components, so-called radial Dunkl processes. The latter generalize eigenvalues processes of some matrix-valued processes and reduces to reflected Brownian motion in Weyl chambers. Besides, Brownian motion in Weyl chambers corresponds to all multiplicity values equal one are constructed from a Brownian motion killed when it first hits the boundary of the Weyl chamber using the unique positive harmonic function (up to a constant) on the Weyl chamber. In the analytic side, determinantal formulas appear and are related to harmonic analysis on the Gelfand pair (Gl(n,C), U(n)). This is in agreement on the one side with the so-called reflection principle in stochastic processes theory and matches on the other side the so-called shift principle introduced by E. Opdam. Finally, I'll discuss the spectacular result of Biane-Bougerol-O'connell yielding to a Duistermaat-Heckman distribution for non crystallographic systems.
2013/01/30
Geometry Colloquium
10:30-12:00 Room #128 (Graduate School of Math. Sci. Bldg.)
Ryoichi Kobayashi (Nagoya University)
Hamiltonian Volume Minimizing Property of Maximal Torus Orbits in the Complex Projective Space (JAPANESE)
Ryoichi Kobayashi (Nagoya University)
Hamiltonian Volume Minimizing Property of Maximal Torus Orbits in the Complex Projective Space (JAPANESE)
[ Abstract ]
We prove that any $U(1)^n$-orbit in $\\Bbb P^n$ is volume minimizing under Hamiltonian deformation.
The idea of the proof is :
- (1) We extend one $U(1)^n$-orbit to the momentum torus fibration $\\{T_t\\}_{t\\in\\Delta^n}$ and consider its Hamiltonian deformation $\\{\\phi(T_t)\\}_{t\\in\\Delta^n}$ where $\\phi$ is a Hamiltobian diffeomorphism of $\\Bbb P^n$,
and then :
- (2) We compare each $U(1)^n$-orbit and its Hamiltonian deformation by compaing the large $k$ asymptotic behavior of the sequence of projective embeddings defined, for each $k$, by the basis of $H^0(\\Bbb P^n,\\Cal O(k))$ obtained by semi-classical approximation of the $\\Cal O(k)$ Bohr-Sommerfeld tori of the Lagrangian torus fibration $\\{T_t\\}_{t\\in\\Delta^n}$ and its Hamiltonian deformation $\\{\\phi(T_t)\\}_{t\\in\\Delta^n}$.
We prove that any $U(1)^n$-orbit in $\\Bbb P^n$ is volume minimizing under Hamiltonian deformation.
The idea of the proof is :
- (1) We extend one $U(1)^n$-orbit to the momentum torus fibration $\\{T_t\\}_{t\\in\\Delta^n}$ and consider its Hamiltonian deformation $\\{\\phi(T_t)\\}_{t\\in\\Delta^n}$ where $\\phi$ is a Hamiltobian diffeomorphism of $\\Bbb P^n$,
and then :
- (2) We compare each $U(1)^n$-orbit and its Hamiltonian deformation by compaing the large $k$ asymptotic behavior of the sequence of projective embeddings defined, for each $k$, by the basis of $H^0(\\Bbb P^n,\\Cal O(k))$ obtained by semi-classical approximation of the $\\Cal O(k)$ Bohr-Sommerfeld tori of the Lagrangian torus fibration $\\{T_t\\}_{t\\in\\Delta^n}$ and its Hamiltonian deformation $\\{\\phi(T_t)\\}_{t\\in\\Delta^n}$.
Lectures
17:30-18:30 Room #122 (Graduate School of Math. Sci. Bldg.)
Antonio Degasperis (La Sapienza, University of Rome)
Integrable nonlinear wave equations, nonlocal interaction and spectral methods (ENGLISH)
Antonio Degasperis (La Sapienza, University of Rome)
Integrable nonlinear wave equations, nonlocal interaction and spectral methods (ENGLISH)
[ Abstract ]
A general class of integrable nonlinear multi-component wave equations are discussed to show that integrability, as implied by Lax pair, does not necessarily imply solvability of the initial value problem by spectral methods. A simple instance of this class, with applicative relevance to nonlinear optics, is discussed as a prototype model. Conservation laws and special solutions of this model are displayed to underline the integrability issue.
A general class of integrable nonlinear multi-component wave equations are discussed to show that integrability, as implied by Lax pair, does not necessarily imply solvability of the initial value problem by spectral methods. A simple instance of this class, with applicative relevance to nonlinear optics, is discussed as a prototype model. Conservation laws and special solutions of this model are displayed to underline the integrability issue.
Lectures
17:30-18:30 Room #122 (Graduate School of Math. Sci. Bldg.)
Antonio Degasperis (La Sapienza, University of Rome)
Integrable nonlinear wave equations, nonlocal interaction and spectral methods (ENGLISH)
Antonio Degasperis (La Sapienza, University of Rome)
Integrable nonlinear wave equations, nonlocal interaction and spectral methods (ENGLISH)
[ Abstract ]
A general class of integrable nonlinear multi-component wave equations are discussed to show that integrability, as implied by Lax pair, does not necessarily imply solvability of the initial value problem by spectral methods. A simple instance of this class, with applicative relevance to nonlinear optics, is discussed as a prototype model. Conservation laws and special solutions of this model are displayed to underline the integrability issue.
A general class of integrable nonlinear multi-component wave equations are discussed to show that integrability, as implied by Lax pair, does not necessarily imply solvability of the initial value problem by spectral methods. A simple instance of this class, with applicative relevance to nonlinear optics, is discussed as a prototype model. Conservation laws and special solutions of this model are displayed to underline the integrability issue.
Lectures
17:30-18:30 Room #122 (Graduate School of Math. Sci. Bldg.)
Antonio Degasperis (La Sapienza, University of Rome)
Integrable nonlinear wave equations, nonlocal interaction and spectral methods (ENGLISH)
Antonio Degasperis (La Sapienza, University of Rome)
Integrable nonlinear wave equations, nonlocal interaction and spectral methods (ENGLISH)
[ Abstract ]
A general class of integrable nonlinear multi-component wave equations are discussed to show that integrability, as implied by Lax pair, does not necessarily imply solvability of the initial value problem by spectral methods. A simple instance of this class, with applicative relevance to nonlinear optics, is discussed as a prototype model. Conservation laws and special solutions of this model are displayed to underline the integrability issue.
A general class of integrable nonlinear multi-component wave equations are discussed to show that integrability, as implied by Lax pair, does not necessarily imply solvability of the initial value problem by spectral methods. A simple instance of this class, with applicative relevance to nonlinear optics, is discussed as a prototype model. Conservation laws and special solutions of this model are displayed to underline the integrability issue.
Lectures
09:45-10:45 Room #123 (Graduate School of Math. Sci. Bldg.)
Marzieh Forough (Ferdowsi Univ. Mashhad)
Stability of Fredholm property of regular operators on Hilbert $C^*$-modules (ENGLISH)
Marzieh Forough (Ferdowsi Univ. Mashhad)
Stability of Fredholm property of regular operators on Hilbert $C^*$-modules (ENGLISH)
Lectures
11:00-12:00 Room #123 (Graduate School of Math. Sci. Bldg.)
Gerardo Morsella (Univ. Roma II)
Scaling algebras, superselection theory and asymptotic morphisms (ENGLISH)
Gerardo Morsella (Univ. Roma II)
Scaling algebras, superselection theory and asymptotic morphisms (ENGLISH)
Lectures
13:30-14:30 Room #123 (Graduate School of Math. Sci. Bldg.)
Joav Orovitz (Ben-Gurion Univ.)
Tracially $\\mathcal{Z}$-absorbing $C^*$-algebras (ENGLISH)
Joav Orovitz (Ben-Gurion Univ.)
Tracially $\\mathcal{Z}$-absorbing $C^*$-algebras (ENGLISH)
Lectures
14:45-15:45 Room #118 (Graduate School of Math. Sci. Bldg.)
Nicola Watson (Univ. Toronto)
Noncommutative covering dimension (ENGLISH)
Nicola Watson (Univ. Toronto)
Noncommutative covering dimension (ENGLISH)
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