次回のセミナー (Next Seminar)
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 |
|---|---|
| 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 |
最近のセミナー (Recent Seminars)
| 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: | |
| 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 |
|---|---|
| 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 |