Domain walls (DWs) are very common objects that appear in many BSM models with spontaneous breaking of discrete symmetries and have been widely studied in the context of gravitational wave observation. Depending on models, DWs can contain internal degrees of freedom such as fermionic zeromodes (like DW fermion in lattice QCD) or bosonic zeromodes. Such an object is called current-carrying DW as it can carry (dark) electric charge/current. In this talk, we will show gravitational wave spectrum radiated from current-carrying DWs can be quite different from conventional DWs. Particularly they can enhance UV regime of spectrum, increasing the detectability by future gravitational wave instruments.

https://www-conf.kek.jp/kincha/
集積回路を中心とした半導体デバイスは現代の電子機器や情報化社会の根幹を支えており、物理実験においてもセンサの微細化、多チャンネル化に伴い高機能・高集積を実現する集積回路技術の重要度は日々増しています。
集積回路技術は今日まで約60年にわたりムーアの法則とも呼ばれるトランジスタの微細化と共に発展して来ました。しかしながら単純な微細化は物理的制約により終わりを迎え、今後の開発競争の見通しは困難なものとなっています。
日本国内では改めて半導体が国家の今後を左右する戦略物資として見直され、先端集積回路製造工場の誘致及び建設、並びにそれを支える人材育成の教育体制の構築と様々な動きが生じています。
本講演ではCMOS集積回路技術を中心とした半導体技術トレンドを俯瞰し、今後の物理実験に用いられるASICの開発のあり方について主観多めに論じます。

We propose a quantum mechanical theory of quantum spaces described by large $N$ noncommutative geometry as a model for quantum gravity. The theory admits fuzzy sphere and fuzzy ellipsoid as solution. We show that these solutions reproduces precisely the horizon radius of a Schwarzschild black hole and a Kerr black hole. Moreover our quantum mechanical description gives rise to a set of microstates over these geometries, which reproduces precisely the Bekenstein-Hawking entropy of black hole. These results provide strong support that our proposed theory of quantum spaces is a plausible candidate for the theory of quantum gravity.

References:
[1] 2406.01466 [hep-th]
A Matrix Model Proposal for Quantum Gravity and the Quantum Mechanics of Black Holes
[2] 2406.12704 [hep-th]
Quantum Kerr Black Hole from Matrix Theory of Quantum Gravity
[3] Recent unpublished results.

Understanding the nature of Dark Matter is one of the most significant open problems in particle physics and cosmology. In this talk, I will explore how Dark Matter candidates can naturally arise as composite bound states in new strongly coupled gauge sectors. I will focus on two specific realizations.
First, I will discuss baryonic Dark Matter in the context of a model for neutrino mass generation. Then, I will examine a model of dark pions, demonstrating how the inclusion of a topological theta term can induce resonant processes, which allow to reproduce the correct Dark Matter relic abundance and address the small-scale anomalies of the Lambda-CDM model.

Understanding the thermalization process of non-abelian plasmas is of great interest, particularly in cosmology and in relativistic heavy ion collisions. On the one hand, the dynamics of thermalization might have had important consequences at the end of the inflationary epoch in the early Universe. On the other hand, out-of-equilibrium Quantum Chromodynamics (QCD) can nowadays be studied in a repeated and systematic manner in relativistic heavy ion collisions (HICs). For the most part, HICs have been used to characterize the high-temperature phase of QCD, quark-gluon plasma, which behaves as a near-perfect fluid during the period of the collision when the temperature is above the deconfinement transition temperature. Nonetheless, our understanding of the process by which local thermal equilibrium is attained (“hydrodynamization”) in heavy ion collisions affects our interpretation of many observables in such collisions. Therefore, it is crucial to have qualitative and quantitative control over the thermalization/hydrodynamization process of QCD. In this talk, we will discuss a recent development in our understanding of the dynamics of hydrodynamization of Yang-Mills plasmas. Specifically, we focus on the weakly coupled description of a pure glue plasma in the framework of kinetic theory. Due to the nonlinear nature of the kinetic equation, finding intuitive and systematic organizing principles to study the dynamics of the distribution function starting from arbitrary initial conditions has proved to be challenging. Adiabatic Hydrodynamization is a novel framework that aims to provide such an organizing principle by identifying the long-lived solutions of the theory as the low-energy eigenstates of the time evolution operator of the theory (the “Hamiltonian”), provided that the (time-dependent) basis on which the Hamiltonian is formulated be such that the evolution is adiabatic. We work this out explicitly in a simplified version of QCD kinetic theory in a geometry motivated by HIC experiments. We conclude by laying out the prospects for studying more general kinetic theories in this framework.

Light hypothetical particles with masses up to O(100) MeV can be produced in the core of supernovae. Their subsequent decays to neutrinos can produce a flux component with higher energies than the standard flux. We study the impact of heavy neutral leptons, Z′bosons, in particular U(1)Lμ−Lτ and U(1)B−L gauge bosons, and majorons coupled to neutrinos flavor-dependently. We obtain new strong limits on these particles from no events of high-energy SN 1987A neutrinos and their future sensitivities from observations of galactic supernova neutrinos.

https://www-conf.kek.jp/kincha/
低エネルギー有効場の理論のうちで、量子重力と無矛盾に結合できるものをLandscape、できないものをSwamplandと呼ぶ。LandscapeとSwamplandを分類する問題は量子重力の沼地問題と言い、近年よく研究されている。本講演では、沼地問題のいくつかの予想とその証拠・証明あるいは応用についてお話ししたい。

Conformal field theories are characterized by structure constants (3-point correlation functions). In order for the theory to be consistent, the structure constants must satisfy the “bootstrap equation”, which is useful to numerically solve, for example, for the critical exponent of the 3d Ising model. From a mathematical point of view, the bootstrap equation arises from the operad structure of spacetime, and such mathematics may be useful to find (as yet undiscovered) constraints on quantum field theory. In this talk, we will introduce the notion of operad and discuss the relation between operads and operator product expansions based on mathematical studies of conformal field theories in two dimensions.

The IKKT matrix model is viewed as a gauge theory of space-time and matter, which arises through an analog of the Higgs effect on suitable vacua, describing 3+1 dimensional space-time branes in the weak coupling regime. In particular, we consider vacua where the SO(9,1) invariance is spontaneously broken to SO(3,1). These vacua describe a cosmological FLRW space-time, on which (an extended version of) gravity arises through quantum effects. Some progress towards understanding the resulting physics is discussed.

On February 23, 1987, neutrinos from a supernova explosion in the Large Magellanic Cloud were observed for the first time in the world. Observations of supernova neutrinos, which are emitted from supernova explosions caused by gravitational collapse at the center of massive stars during the final stage of their evolution, are important for various topics in astrophysics, including the history of star formation and the mechanism of supernova explosions. Therefore, supernova neutrinos have been actively studied both observationally and theoretically. In particular, Super-Kamiokande, which which began a new stage of operations as SK-Gd in 2020, is expected to bring drastic progress in supernova neutrino research, especially in the measurement of diffuse supernova neutrino background and the pointing accuracy for nearby supernovae. Furthermore, next-generation large neutrino detectors such as Hyper-Kamiokande will enter a new stage of precision measurements for supernova neutrino observations.
In this seminar, I will discuss recent progress and prospects of supernova neutrino research.