Sunday, July 11, 10:00- iTHEMS Science Outreach Workshop 2021
Friday, July 16, 12:30- Coffee Meeting

On July 2 Mizuki Oikawa gave a talk at the iTHEMS math seminar. He talked about the interaction among modular functions, conformal field theories and moonshine phenomena. Below is a recap of his talk. The j-invariant is an example of modular form. Its coefficients in the q-expansion is closely related to a certain sporadic simple group (the monster group), and the relation can be understood via the theory of vertex operator algebras (VOA), which is a mathematical model of conformal field theory (CFT). This gives an example of moonshine phenomena. On the other hand, there is another mathematical framework for CFT, called the conformal net, which depends on the theory of von Neumann algebras. Carpi-Kawahigashi-Longo-Weiner gave a correspondence between a certain class of VOAs (which includes the monstrous moonshine VOA) and that of conformal nets. Recently, Tener gave a geometric realization of some VOAs and the corresponding conformal nets via Segal CFT. The talk was highly stimulating, and the audience asked many questions that arise from both mathematical and physical sides.

Reported by Michiya Mori

On July 1st, Prof. Takahiro Sakaue (Aoyama Gakuin University) gave us a talk about chromatin dynamics in C. elegans embryos. He first introduced important factors for gene expression such as phase separation, topological constraints, and chromatin dynamics. After explaining how to see the chromatin dynamics under the microscope, he showed us interesting experimental results about the dependence of MSD on the nucleus radius. By considering polymer models, he showed that two kinds of typical length/time scales appear and discussed how the type of anomalous diffusion of chromatin is determined depending on the time/length scale. Moreover, he theoretically explained the observed nucleus-size dependence of MSD. We are grateful to Sakaue-san for the exciting talk!

Reported by Kyosuke Adachi

I'm Etsuko Itou, a Postdoctoral Researcher (Concurrent) since July 2021. I'm interested in quantum field theories, in particular, quantum chromodynamics (QCD) in extreme regimes. Although QCD in the superfluid phase, which occurs in low-temperature and high-density regimes, is still an unsolved area due to the infamous sign problem, a theoretical understanding is urgently needed in relation to neutron star physics. I am working on various numerical approaches to understanding quantum field theories with the sign problem. For example, I utilize the conventional classical supercomputers to study qualitative properties of modified QCD without the sign problem, and I develop quantum computation algorithms based on a new formula where the sign problem does not emerge.

Title: The maximal negative ion of molecules in Schrödinger, Hartree-Fock, and Müller theories
Author: Yukimi Goto
arXiv: http://arxiv.org/abs/2107.01826v2

Title: Positivity vs. Lorentz-violation: an explicit example
Author: Katsuki Aoki, Shinji Mukohyama, Ryo Namba
arXiv: http://arxiv.org/abs/2107.01755v1

Title: Effects of finite-light-speed correction for the Coulomb interaction on nuclear binding energies and radii in spherical nuclei
Author: Tomoya Naito
arXiv: http://arxiv.org/abs/2106.14270v1

Title: Goldstone Boson Scattering with a Light Composite Scalar
Author: T. Appelquist, R. C. Brower, K. K. Cushman, G. T. Fleming, A. Gasbarro, A. Hasenfratz, J. Ingoldby, X. Y. Jin, J. Kiskis, E. T. Neil, J. C. Osborn, C. Rebbi, E. Rinaldi, D. Schaich, P. Vranas, E. Weinberg, O. Witzel
arXiv: http://arxiv.org/abs/2106.13534v1

Title: Quantum hydrodynamics from local thermal pure states
Author: Shoichiro Tsutsui, Masaru Hongo, Shintaro Sato, Takahiro Sagawa
arXiv: http://arxiv.org/abs/2106.12777v2

Title: Modulus sheaves with transfers
Author: Shane Kelly, Hiroyasu Miyazaki
arXiv: http://arxiv.org/abs/2106.12837v1

Title: Unitary $p$-wave Fermi gas in one dimension
Author: Hiroyuki Tajima, Shoichiro Tsutsui, Takahiro M. Doi, Kei Iida
arXiv: http://arxiv.org/abs/2106.12909v1