Shigenori Otsuka received "FY2019 Researcher Incentive Award (桜舞賞)" on March 10, 2020 for his achievements in the "Development of a novel three-dimensional precipitation nowcast method and its real-time demonstration". Congratulations!

The QFT-core seminar series has been started from this fiscal year. The seminar series is hold under the theme of the Quantum Field Theory including elementary particle theory, nuclear theory and Condensed Matter physics.

The First seminar in the series was given by Dr.Kengo Kikuchi from the Riken iTHEMS on May 15. The title is “Gradient Flow Equation and Its Applications”. The gradient flow is the one of the methods to suppress the ultraviolet divergence in gauge theories. The any correlation functions in terms of the flowed field, which is defined by the gradient flow equation, are finite without additional renormalizations. Because of this surprising property, the methods has been studied widely, especially in the lattice field theory. In this seminar, he introduce what the gradient flow is briefly, and show his work, “generalized gradient flow equation”, which is the gradient flow equation for field theories with nonlinearly realized symmetry. Applying the formalism to a supersymmetric theory and O(N) non linear sigma model, the SUSY gradient flow and the Large N gradient flow are obtained. He also refer to the current research, the gradient flow of the supersymmetric theory with the non-renormalization theorem and the new formalism to obtain the sphalerons, which is one of the static classical solutions, using gradient flow methods.

The seminar was hold via Zoom. There were about 20 participants from iTHEMS and other university. The participants enjoyed meaningful discussions through the seminar.

Math seminar titled "How many electrons can atoms bind?" by Dr. Yukimi Goto was hold on 13 May. In the first part, the speaker started the talk by introducing many body Hamiltonian and Pauli principle. She then introduced the ionization conjecture. She also introduced some known results concerning about this conjecture. In the second part, the speaker introduced approximation methods and its relation to the ionization conjecture. She first introduced Thomas-Fermi theory and see TF functional appears as a leading term of grand state energy for large atom. She introduced Hartree-Fock theory next. She mentioned a variant of the ionization conjecture for HF theory was proven by Solovej, but original conjecture is still open. She then explained HF theory can be regarded as good approximation in terms of volume.

Title: Revisiting relativistic magnetohydrodynamics from quantum electrodynamics
Author: Masaru Hongo, Koichi Hattori
arXiv: http://arxiv.org/abs/2005.10239v1

Title: Obtaining the sphaleron field configurations with gradient flow
Author: Yu Hamada, Kengo Kikuchi
arXiv: http://arxiv.org/abs/2003.02070v2

Title: The Cayley transform in complex, real and graded K-theory
Author: Chris Bourne, Johannes Kellendonk, Adam Rennie
arXiv: http://arxiv.org/abs/1912.07158v2

Title: Janus interface entropy and Calabi's diastasis in four-dimensional N=2 superconformal field theories
Author: Kanato Goto, Lento Nagano, Tatsuma Nishioka, Takuya Okuda
arXiv: http://arxiv.org/abs/2005.10833v1

Title: Low-Dimensional Fluctuations and Pseudogap in Gaudin-Yang Fermi Gases
Author: Hiroyuki Tajima, Shoichiro Tsutsui, Takahiro M. Doi
arXiv: http://arxiv.org/abs/2005.12124v1

Title: Topologies on schemes and modulus pairs
Author: Bruno Kahn, Hiroyasu Miyazaki
arXiv: http://arxiv.org/abs/1910.14595v2

Title: Goldstino spectrum in an ultracold Bose-Fermi mixture with explicitly broken supersymmetry
Author: Hiroyuki Tajima, Yoshimasa Hidaka, Daisuke Satow
arXiv: http://arxiv.org/abs/2001.08507v2