An international collaborative research group led by Maria Dinotti (Senior Research Scientist, iTHEMS) and Shigehiko Nagataki (Deputy Program Director, iTHEMS) has discovered that gamma-ray bursts (GRBs), which occur simultaneously with kilonovae, are effective as standard candles for measuring the distance of the universe.

The results of this research show the potential to make use of GRBs for cosmology in the near future, to estimate the amount of dark energy and dark matter in the universe.

-Calculations show how theoretical ‘axionic strings’ could create odd behavior if produced in exotic materials in the lab-

A hypothetical particle that could solve one of the biggest puzzles in cosmology just got a little less mysterious. A RIKEN physicist and two colleagues have revealed the mathematical underpinnings that could explain how so-called axions might generate string-like entities that create a strange voltage in lab materials[1].

On November 10, Dr. Naoto Shiraishi from Gakushuin University gave a talk entitled “Mathematics of thermalization in isolated quantum systems” at the iTHEMS Math-Phys joint seminar.

In the first part, he reviewed some results and problems of quantum thermalization. Besides, he explained the typicality of equilibrium states, the relaxation caused by large effective dimensions, and the weak/strong eigenstate thermalization hypothesis mathematically.

In the second part, the speaker discussed the difficulty of the thermalization problems and some of his results. Mainly, he showed the absence of local conserved quantities in the S=1/2 XYZ chain with a magnetic field.

The talk had many participants from in and out iTHEMS and many stimulating discussions.

Title: Classification of Magnetic Vortices by Angular Momentum Conservation
Author: Kenji Fukushima, Yoshimasa Hidaka, Ho-Ung Yee
arXiv: http://arxiv.org/abs/2011.06981v1

Title: Variational Shape Approximation of Point Set Surfaces
Author: Martin Skrodzki, Eric Zimmermann, Konrad Polthier
arXiv: https://arxiv.org/abs/2005.01003v2

Title: Firewall From Effective Field Theory
Author: Pei-Ming Ho, Yuki Yokokura
arXiv: https://arxiv.org/abs/2004.04956v3

Title: Parity of the neutron consistent with neutron-antineutron oscillations
Author: Kazuo Fujikawa, Anca Tureanu
arXiv: https://arxiv.org/abs/2009.12843v2

Title: Distance between collapsing matter and trapping horizon in evaporating black holes
Author: Pei-Ming Ho, Yoshinori Matsuo, Yuki Yokokura
arXiv: https://arxiv.org/abs/1912.12863v3

Title: Test of Eigenstate Thermalization Hypothesis Based on Local Random Matrix Theory
Author: Shoki Sugimoto, Ryusuke Hamazaki, Masahito Ueda
arXiv: https://arxiv.org/abs/2005.06379v3

Title: Liouvillian Skin Effect: Slowing Down of Relaxation Processes without Gap Closing
Author: Taiki Haga, Masaya Nakagawa, Ryusuke Hamazaki, Masahito Ueda
arXiv: https://arxiv.org/abs/2005.00824v2

Title: Relativistic density functional theory with finite-light-speed correction for the Coulomb interaction: a non-relativistic-reduction based approach
Author: Tomoya Naito, Ryosuke Akashi, Haozhao Liang, Shinji Tsuneyuki
arXiv: https://arxiv.org/abs/1911.10670v2

Title: Griffiths-McCoy singularity on the diluted Chimera graph: Monte Carlo simulations and experiments on the quantum hardware
Author: Kohji Nishimura, Hidetoshi Nishimori, Helmut G. Katzgraber
arXiv: https://arxiv.org/abs/2006.16219v2

Title: Absence of fast scrambling in thermodynamically stable long-range interacting systems
Author: Tomotaka Kuwahara, Keiji Saito
arXiv: https://arxiv.org/abs/2009.10124v2