次回のセミナー (Next Seminar)
TBA
| When: | 2026/10/07 (Wed.) 16:00-17:00 |
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| Where: | Honkan (Main Bldg.) H2-39 |
| Speaker: | Tomohito Shiga (Rikkyo University) |
| Abstract: | TBA |
| Reference: | arXiv:2605.01321, ongoing work |
最近のセミナー (Recent Seminars)
Fermionic modes of D-instanton wormholes from broken local supersymmetry
| When: | 2026/10/30 (Fri.) 13:30-14:30 |
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| Where: | Honkan (Main Bldg.) H2-39 |
| Speaker: | Shoichi Kawamoto (NITEP, Oberlin University) |
| Abstract: | In low-energy supergravity treatment of type IIB superstring on general D-instanton wormhole profiles in the bulk, we obtain non-vanishing scalar two-point functions in addition to the vanishing $\langle \tau^* \tau^* \rangle$ that corresponds to the BPS amplitude detected by two D-instantons at their respective boundaries. This is exploited to show that the modes of broken local supersymmetry in the bulk deliver the fermionic (diagonal) modes on the boundaries through the deformation by the form of current-current two point functions propagating on the tree level cylinder geometry. Our treatment is generalizable to multi D-instanton cases and general Euclidean branes. |
| Reference: | arXiv:2604.14508 |
TBA
| When: | 2026/10/21 (Wed.) 16:00-17:00 |
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| Where: | Honkan (Main Bldg.) H2-39 |
| Speaker: | Shota Saito (IPMU) |
| Abstract: | TBA |
| Reference: | arXiv:2608.06093 |
TBA
| When: | 2026/10/07 (Wed.) 16:00-17:00 |
|---|---|
| Where: | Honkan (Main Bldg.) H2-39 |
| Speaker: | Tomohito Shiga (Rikkyo University) |
| Abstract: | TBA |
| Reference: | arXiv:2605.01321, ongoing work |
3d Chern–Simons matter theories from generalized Argyres–Douglas theories
| When: | 2026/07/29 (Wed.) 16:00-17:00 |
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| Where: | Honkan (Main Bldg.) H174 |
| Speaker: | Yutaka Yoshida (Meiji Gakuin University) |
| Abstract: | 近年、4d $\mathcal{N}=2$ 超共形場理論のSchur指数、あるいは対応するVOAの真空指標のNahm和公式を手がかりとして、3d $\mathcal{N}=2$ Chern--Simons matter理論を構成する一連の研究が行われてきた。このように構成されたChern--Simons matter理論は、適切なモノポール・スーパーポテンシャルを導入することで、赤外領域において超対称性が拡大し、4d $\mathcal{N}=2$ SCFTのある種の3次元簡約(R-twisted reduction)によって得られる3d $\mathcal{N}=4$ 超共形場理論へフローすると考えられている。本講演では、まずこの構成法の一般的な枠組みとその歴史的発展を概観する。その後、我々が行った、$\gcd(M, N)=1$を満たす$(A_{M-1},A_{N-1})$型および$(A_2,D_4)$型Argyres--Douglas理論の3次元簡約を実現するChern--Simons matter理論の構成と、その物理的性質について説明する。 この講演は、西中崇博氏との共同研究 arXiv:2512.15201 [hep-th]、および濱近諒氏、西中崇博氏、谷川昇右氏との共同研究 arXiv:2607.19021 [hep-th]に基づく。 |
| Reference: | arXiv:2512.15201, arXiv:2607.19021 |
Exact WKB analysis of inverted triple-well: resonance, PT-symmetry breaking, and resurgence
| When: | 2026/07/22 (Wed.) 16:00-17:00 |
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| Where: | Honkan (Main Bldg.) H174 |
| Speaker: | Syo Kamata (The University of Tokyo) |
| Abstract: | We study non-Hermitian quantum mechanics of an inverted triple-well potential within the exact WKB framework. For a single classical potential, different Siegert boundary conditions define three distinct quantum problems: the PT-symmetric, resonance, and anti-resonance systems. For each case, we derive the exact quantization condition and construct the associated trans-series solution. By identifying the resurgent structures and cancellations in these non-Hermitian setups, we obtain the median-summed series, clarifying when the spectra are real or complex in accordance with the physical properties of each system. Establishing explicit links to the semi-classical path integral formalism, we elucidate the roles of bounce and bion configurations in these non-Hermitian systems. This analysis predicts PT-symmetry breaking, which we also verify numerically. Using the median quantization conditions, we prove the existence of this symmetry breaking and establish an exact equation for the exceptional point, which emerges as a remarkably simple algebraic relation between the bounce and bion actions. We further show that the median-summed non-perturbative correction to the spectrum vanishes at the exceptional point, while the resurgent structure survives through a universal minimal trans-series. For the resonance and anti-resonance systems, we find that the exact median-summed spectra are related by complex conjugation, representing time reversal in this setting, are necessarily complex, and do not exhibit an exceptional point. Although their spectra differ significantly from the PT-symmetric case, they share the same minimal trans-series. By maintaining explicit links with the path integral saddles and the formal theory of resurgence, our analysis provides a unified and general perspective on the quantization of non-Hermitian theories. This talk is based on: Syo Kamata and Tatsuhiro Misumi and Cihan Pazarbaşı and Hidetoshi Taya, "Exact WKB analysis of inverted triple-well: resonance, PT-symmetry breaking, and resurgence, " arXiv:2604.05878 [hep-th]. |
| Reference: | arXiv:2604.05878 |
Decrease of the entanglement entropy of the Hawking radiation induced by backreaction in the Bose-Einstein condensate
| When: | 2026/06/12 (Fri.) 12:30-13:30 |
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| Where: | Honkan (Main Bldg.) H174 |
| Speaker: | Tsunehide Kuroki (Toyota Technological Institute) |
| Abstract: | We analytically study the effect of backreaction from analog Hawking radiation on its entanglement entropy in the Bose-Einstein condensate (BEC). The backreaction is expected to play an essential role in the decrease of the entanglement entropy and in realizing the Page curve. Since the BEC theory has microscopic Hamiltonian and thus exhibits unitarity, it is desirable to reproduce the Page curve explicitly by using the Hamiltonian. As the first step to analyze this in a concrete example, we study the BEC with a step-like configuration that has been extensively studied in the literature. By using the microscopic theory, we derive an explicit form of backreaction from analog Hawking radiation. Combining it with the known results of the Bogoliubov coefficients, we analytically compute the entanglement entropy of the Hawking radiation, and show that it decreases as expected due to the backreaction for sufficiently low energy modes over a wide range of the parameter characterizing the step-like configuration. |
| Reference: | arXiv:2604.14824 |
dS/CFT対応におけるアインシュタイン方程式と第一法則
| When: | 2026/05/29 (Fri.) 12:30-13:30 |
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| Where: | Honkan (Main Bldg.) H174 |
| Speaker: | Kosei Fujiki (YITP) |
| Abstract: | AdS/CFT対応の枠組みにおいて、アインシュタイン方程式とエンタングルメントエントロピーの第一法則が等価であることが示されている。本講演では、この関係をdS/CFT対応の枠組みで議論する。具体的には、dS時空における計量の一次摂動を考え、線形化アインシュタイン方程式を解く。その解を用いて、適切に第一法則を満たすような、dS/CFT対応におけるエンタングルメントエントロピーの極小曲面の取り方を提案する。本研究は基礎物理学研究所の小原充貴氏、新名宏太朗氏、鈴木優樹氏、高柳匡氏との共同研究に基づく。 |
| Reference: | arXiv:2511.07915 |
More on Higgsing of D-type conformal matter from web diagrams
| When: | 2026/05/15 (Fri.) 12:30-13:30 |
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| Where: | Honkan (Main Bldg.) H174 |
| Speaker: | Hirotaka Hayashi (Tokai University) |
| Abstract: | We revisit Higgsing of D-type conformal matter theories compactified on a circle from web diagrams with trivalent gluing. We argue that the Higgsing yields a web diagram for the 5d theory which arises from a circle compactification of the 6d SO(12) gauge theory with half-hypermultiplets in two different spinor representations and also web diagrams for the 5d theories arising from a twisted compactification of the 6d SO(12)/SO(11) gauge theories with spinor matter. It is also possible to apply the topological vertex to the web diagrams and compute the partition functions of the 5d theories. |
| Reference: | ongoing work |
D型変形W代数と運動の保存量
| When: | 2026/04/22 (Wed.) 16:00-17:00 |
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| Where: | Honkan (Main Bldg.) H174 |
| Speaker: | Michio Jimbo (Rikkyo University) |
| Abstract: | 共形場理論における運動の保存量, およびそのq変形は, KdV型古典可積分階層のハミルトニアンの量子化にあたる可積分系として興味深い. glN型変形W代数については量子トロイダル代数に基づいた構成が知られているが, A型以外についての研究はあまり進んでいない. ここでは問題の背景から始め, D型の場合の計算結果を紹介し, その代数的背景を解説する. 本研究は山形大学の小島武夫氏との共同研究である. |
| Reference: | arXiv:2509.23588 |