過去の記録 ~07/14本日 07/15 | 今後の予定 07/16~


10:30-12:00   数理科学研究科棟(駒場) 128号室
本多宣博 氏 (東北大学)
Classification of Moishezon twistor spaces on 4CP^2 (JAPANESE)



11:00-14:30   数理科学研究科棟(駒場) 117号室
Alexander Orlov 氏 (Nonlinear Wave Processes Laboratory, Oceanology Institute (Moscow)) 11:00-12:00
CKP Hierarchy, Bosonic Tau Function, Bosonization Formulae and Orthogonal Polynomials both in Odd and Even Variables
(based on a joint work with Johan van de Leur and Takahiro Shiota) (ENGLISH)
[ 講演概要 ]
We develop the theory of CKP hierarchy introduced in the papers of Kyoto school where the CKP tau function is written as a vacuum expectation value in terms of free bosons. We show that a sort of odd currents naturaly appear. We consider bosonization formulae which relate bosonic Fock vectors to polynomials in even and odd Grassmannian variables, where both sets play a role of higher times.
増田恭穂 氏 (神戸大学) 13:30-14:30
van Diejenの$q$差分作用素に対する核関係式と
多重$q$超幾何級数の変換公式 (JAPANESE)
[ 講演概要 ]
$BC$型のCauchy型核関数がKoornwinderの$q$差分作用素に対して, ある関係式を満たすことが知られている. 本講演ではこの結果を一般化して, 核関数とvan Diejenの$q$差分作用素族との関係を述べる. また,この関係式から現れる2種類の多重$q$超幾何級数の変換公式を紹介する.



15:00-16:10   数理科学研究科棟(駒場) 000号室
本セミナーはITスタジオで開かれます.参加希望の方は事前に東大数理 鎌谷研吾( kengok at ms.u-tokyo.ac.jp)までお問い合わせください.
清 智也 氏 (慶應義塾大学 理工学部 数理科学科)
定常な最適輸送写像から作られる統計モデル (JAPANESE)
[ 講演概要 ]
輸送コストの定義が Gray, Neuhoff and Shields (1975) によって与えられている.
本研究の一部は,Ludger Rueschendorf 教授との共同研究である
[ 参考URL ]



16:30-18:00   数理科学研究科棟(駒場) 056号室
Tea: 16:00 - 16:30 コモンルーム
Andrei Pajitnov 氏 (Univ. de Nantes, Univ. of Tokyo)
Circle-valued Morse theory for complex hyperplane arrangements (ENGLISH)
[ 講演概要 ]
Let A be a complex hyperplane arrangement
in an n-dimensional complex vector space V.
Denote by H the union of the hyperplanes
and by M the complement to H in V.

We develop the real-valued and circle-valued Morse
theory on M. We prove that if A is essential then
M has the homotopy type of a space
obtained from a finite n-dimensional
CW complex fibered over a circle,
by attaching several cells of dimension n.

We compute the Novikov homology of M and show
that its structure is similar to the
homology with generic local coefficients:
it vanishes for all dimensions except n.

This is a joint work with Toshitake Kohno.


16:30-18:00   数理科学研究科棟(駒場) 126号室
大島芳樹 氏 (東京大学大学院数理科学研究科)
コホモロジカル誘導の局所化 (ENGLISH)
[ 講演概要 ]
コホモロジカル誘導は(g,K)-加群に対して代数的に定義され、半単純リー群の離散系列表現、主系列表現(のHarish-Chandra加 群)、Zuckerman加群などを生成する。
Borel部分代数の1次元表現からの誘導の場合、誘導された表現は旗多様体のD加群を用いて実現できることが,Hecht, Milicic, Schmid, Wolfにより示されている。



13:30-16:00   数理科学研究科棟(駒場) 117号室
Leonid Rybnikov 氏 (IITP, and State University Higher School of Economics,
Department of Mathematics) 13:30-14:30
Quantization of Quasimaps' Spaces (joint work with M. Finkelberg) (ENGLISH)
[ 講演概要 ]
Quasimaps' space Z_d (also known as Drinfeld's Zastava space) is a
remarkable compactification of the space of based degree d maps from
the projective line to the flag variety of type A. The space Z_d has a
natural Poisson structure,
which goes back to Atiyah and Hitchin. We describe
the Quasimaps' space as some quiver variety, and define the
Atiyah-Hitchin Poisson structure in quiver terms.
This gives a natural way to quantize this Poisson structure.
The quantization of the coordinate ring of the Quasimaps' space turns
to be some natural subquotient of the Yangian of type A.
I will also discuss some generalization of this result to the BCD types.
Anton Zabrodin 氏 (
Instituteof Biochemical Physics) 15:00-16:00
Quantum integrable models with elliptic R-matrices
and elliptic hypergeometric series (ENGLISH)
[ 講演概要 ]
Intertwining operators for infinite-dimensional representations of the
Sklyanin algebra with spins l and -l-1 are constructed using the technique of
intertwining vectors for elliptic L-operator. They are expressed in
terms of
elliptic hypergeometric series with operator argument. The intertwining
operators obtained (W-operators) serve as building blocks for the
elliptic R-matrix
which intertwines tensor product of two L-operators taken in
representations of the Sklyanin algebra with arbitrary spin. The
Yang-Baxter equation
for this R-matrix follows from simpler equations of the star-triangle
type for the
W-operators. A natural graphic representation of the objects and
equations involved
in the construction is used.



16:30-18:00   数理科学研究科棟(駒場) 270号室
O. Emanouilov 氏 (Colorado State University)
On reconstruction of Lame coefficients from partial Cauchy data (ENGLISH)
[ 講演概要 ]
For the isotropic Lame system, we prove that if the Lame coefficient ¥mu is a positive constant, then both Lame coefficients can be recovered from the partial Cauchy data.



17:30-18:30   数理科学研究科棟(駒場) 056号室
Andrei Suslin 氏 (Northwestern University)
K_2 of the biquaternion algebra (ENGLISH)
[ 参考URL ]



10:30-12:00   数理科学研究科棟(駒場) 128号室
神島 芳宣 氏 (首都大学東京)
Compact locally homogeneous Kähler manifolds $\Gamma\backslash G/K$ (JAPANESE)



15:00-16:10   数理科学研究科棟(駒場) 000号室
本セミナーはITスタジオで開かれます.参加希望の方は事前に東大数理 鎌谷研吾( kengok at ms.u-tokyo.ac.jp) までお問い合わせください.
鈴木 大慈 氏 (東京大学情報理工学系研究科)
On Convergence Rate of Multiple Kernel Learning with Various Regularization Types (JAPANESE)
[ 講演概要 ]
本発表ではMultiple Kernel Learning (MKL) の統計的な収束レートを様々な正則化項に関して議論する. 近年の数値実験によると,スパースなL1正則化は必ずしもデンスな正則化よりも良い性能を示すとは限らない. そこで,我々はエラスティックネットやLpノルムを含む様々な正則化に関して収束レートを議論する.そのため, 二つの状況(真がスパースな状況および真がデンスな状況)に分けて議論を進める. スパースな状況ではエラスティックネットが真の滑らかさを適切に捉える事が出来ることを示す.デンスな状況では, 再生核ヒルベルト空間の複雑さのばらけ具合が最適な正則化項の決定に影響することを示す. すなわち,複雑さが一様な場合はL1が,非一様な場合はデンスな正則化が好ましいことが示される.
[ 参考URL ]



17:00-18:00   数理科学研究科棟(駒場) 056号室
Tea: 16:40 - 17:00 コモンルーム
Gael Meigniez 氏 (Univ. de Bretagne-Sud, Chuo Univ.)
Making foliations of codimension one,
thirty years after Thurston's works
[ 講演概要 ]
In 1976 Thurston proved that every closed manifold M whose
Euler characteristic is null carries a smooth foliation F of codimension
one. He actually established a h-principle allowing the regularization of
Haefliger structures through homotopy. I shall give some accounts of a new,
simpler proof of Thurston's result, not using Mather's homology equivalence; and also show that this proof allows to make F have dense leaves if dim M is at least 4. The emphasis will be put on the high dimensions.


16:30-18:00   数理科学研究科棟(駒場) 128号室
和田出 秀光 氏 (早稲田大学(日本学術振興会特別研究員PD))
重み付きTrudinger-Moser型不等式の最良定数に関して (JAPANESE)
[ 講演概要 ]
重みなしの場合は、 Adachi -Tanaka, Proc. Amer. Math. Soc. (1999),



16:30-18:00   数理科学研究科棟(駒場) 122号室
勝良健史 氏 (慶応大学)
Towards the classification of non-simple $C^*$-algebras of real rank zero (ENGLISH)



10:00-11:00   数理科学研究科棟(駒場) 056号室
Chun Liu 氏 (University of Tokyo / Pennsylvania State University)
Energetic Variational Approaches for Ionic Fluids (ENGLISH)
[ 講演概要 ]
In this talk, I will present our recent study on the ionic transport through ion channels in cell membranes. Motivated by our earlier work on energetic variational approaches, developed for various complex fluids, especially electrorheological (ER) fluids (Phys. Rev. Lett. 101, 194503 (2008)), we derived/proposed a coupled system for ionic solutions, which takes into account of the solvent water, the diffusion and electro-static interaction of different ions. In particular, I will emphasize on the selectivity effects of the ion channels, under the simplest geometric and molecular structures.



16:30-18:00   数理科学研究科棟(駒場) 056号室
Tea: 16:00 - 16:30 コモンルーム
松田 能文 氏 (東京大学大学院数理科学研究科)
相対的双曲群の相対的擬凸部分群 (JAPANESE)
[ 講演概要 ]
群の相対的双曲性は語双曲性の一般化としてGromovにより導入された. 相対的
双曲群の例として, 有限体積を持つ完備双曲多様体の基本群が挙げられる. 語双
曲群の擬凸部分群の一般化として, 相対的双曲群の相対的擬凸部分群が定義され
る. Osinにより相対的双曲群の双曲的に埋め込まれた部分群が導入され, 付加的
な代数的性質を持つ相対的擬凸部分群として特徴づけられている. この講演では,
國新一氏, 山形紗恵子氏との最近の共同研究について触れる.



16:30-18:00   数理科学研究科棟(駒場) 056号室
Tea: 16:00 - 16:30 コモンルーム
Clara Loeh 氏 (Univ. Regensburg)
Functorial semi-norms on singular homology (ENGLISH)
[ 講演概要 ]
Functorial semi-norms on singular homology add metric information to
homology classes that is compatible with continuous maps. In particular,
functorial semi-norms give rise to degree theorems for certain classes
of manifolds; an invariant fitting into this context is Gromov's
simplicial volume. On the other hand, knowledge about mapping degrees
allows to construct functorial semi-norms with interesting properties;
for example, so-called inflexible simply connected manifolds give rise
to functorial semi-norms that are non-trivial on certain simply connected



16:00-17:00   数理科学研究科棟(駒場) 370号室
Benny Hon 氏 (Department of Mathematics City University of Hong Kong)
Kernel-based Approximation Methods for Cauchy Problems of Fractional Order Partial Differential Equations (ENGLISH)
[ 講演概要 ]
In this talk we present the recent development of meshless computational methods based on the use of kernel-based functions for solving various inverse and ill-posed problems. Properties of some special kernels such as harmonic kernels; kernels from the construction of fundamental and particular solutions; Green’s functions; and radial basis functions will be discussed. As an illustration, the recent work in using the method of fundamental solutions combined with the Laplace transform and the Tikhonov regularization techniques to solve Cauchy problems of Fractional Order Partial Differential Equations (FOPDEs) will be demonstrated. The main idea is to approximate the unknown solution by a linear combination of fundamental solutions whose singularities are located outside the solution domain. The Laplace transform technique is used to obtain a more accurate numerical approximation of the fundamental solutions and the L-curve method is adopted for searching an optimal regularization parameter in obtaining stable solution from measured data with noises.



10:00-11:15   数理科学研究科棟(駒場) 123号室
權業 善範 氏 (東京大学大学院数理科学研究科)
Abundance conjecture and canonical bundle formula(アバンダンス予想と標準因子公式) (JAPANESE)



16:30-17:30   数理科学研究科棟(駒場) 123号室
お茶&Coffee&お菓子: 16:00~16:30 (コモンルーム)。

石井志保子氏 氏 (東大数理)
弧空間と代数幾何学 (JAPANESE)
[ 講演概要 ]
ジェットスキームや弧空間の概念は 1968年に John F. Nash によって導入された.
このとき彼は弧空間と特異点解消の対応を記述する「Nash 問題」を提起している.



16:00-18:15   数理科学研究科棟(駒場) 123号室
斎藤毅 氏 (東京大学数理科学研究科) 16:00-17:00
Discriminants and determinant of a hypersurface of even dimension (ENGLISH)
[ 講演概要 ]
The determinant of the cohomology of a smooth hypersurface
of even dimension as a quadratic character of the absolute
Galois group is computed by the discriminant of the de Rham
cohomology. They are also computed by the discriminant of a
defining polynomial. We determine the sign involved by testing
the formula for the Fermat hypersurfaces.
This is a joint work with J-P. Serre.
Dennis Eriksson 氏 (University of Gothenburg) 17:15-18:15
Multiplicities of discriminants (ENGLISH)
[ 講演概要 ]
The discriminant of a homogenous polynomial is another homogenous
polynomial in the coefficients of the polynomial, which is zero
if and only if the corresponding hypersurface is singular. In
case the coefficients are in a discrete valuation ring, the
order of the discriminant (if non-zero) measures the bad
reduction. We give some new results on this order, and in
particular tie it to Bloch's conjecture/the Kato-T.Saito formula
on equality of localized Chern classes and Artin conductors. We
can precisely compute all the numbers in the case of ternary
forms, giving a partial generalization of Ogg's formula for
elliptic curves.



16:30-18:00   数理科学研究科棟(駒場) 122号室
Jean Roydor 氏 (Univ. Tokyo)
Almost completely isometric maps and applications (ENGLISH)



16:30-18:00   数理科学研究科棟(駒場) 122号室
Raphael Ponge 氏 (IPMU)
New perspectives for the local index formula in noncommutative geometry (ENGLISH)



15:00-16:10   数理科学研究科棟(駒場) 002号室
矢田 和善 氏 (筑波大学 数理物質科学研究科)
Statistical Inference for High-Dimension, Low-Sample-Size Data (JAPANESE)
[ 講演概要 ]
マイクロアレイデータ, MRIデータ等にみられるように,データの次元数が標本数よりも遥かに大きな高次元小標本データが,解析対象になる場面が増えてきている.通常の多変量解析の枠組みの手法を,高次元小標本にそのまま適用することはできない.それゆえ,高次元小標本における新しい理論と方法論の構築が必要になる. 最近の一連の研究で,高次元小標本データが有する特徴的な幾何学的構造と漸近正規性に着目し,高次元小標本における平均ベクトル・共分散行列の推定・検定, 変数選択, 判別分析, 回帰分析やパスウエイ解析など様々な統計的推測に精度保証を与えるための理論と方法論を与えた.本セミナーでは,これらの統計的推測の中で,高次元小標本における平均ベクトルの推定・検定や判別分析などを中心に最新の結果を数値例と実際の解析例を交え,紹介する.本研究は青嶋教授(筑波大学)との共同研究です.
[ 参考URL ]



16:30-18:00   数理科学研究科棟(駒場) 128号室
小林 政晴 氏 (東京理科大学)
The inclusion relation between Sobolev and modulation spaces (JAPANESE)
[ 講演概要 ]
In this talk, we consider the inclusion relations between the $L^p$-Sobolev spaces and the modulation spaces. As an application, we give mapping properties of unimodular Fourier multiplier $e^{i|D|^\\alpha}$ between $L^p$-Sobolev spaces and modulation spaces.
Joint work with Mitsuru Sugimoto (Nagoya University).


16:30-18:00   数理科学研究科棟(駒場) 056号室
Tea: 16:00 - 16:30 コモンルーム
川室 圭子 氏 (University of Iowa)
The self linking number and planar open book decomposition (ENGLISH)
[ 講演概要 ]
I will show a self linking number formula, in language of
braids, for transverse knots in contact manifolds that admit planar
open book decompositions. Our formula extends the Bennequin's for
the standar contact 3-sphere.

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