226 citations · 1.4k across the 35 of their papers we have counts for
36 papers
Diffusion Language Models as Open Quantum Systems
Akinori Tanaka, Yukinao Akamatsu, Takuki Tomita +1
Diffusion language models generate text by reversing a classical diffusion process over token sequences. We show that their continuous-time forward and reverse dynamics can be embe…
Effective field theory for dissipative photons from higher-form symmetries
Genki Yoshimura, Yukinao Akamatsu, Yuji Hirono
Recent developments in generalized symmetries have provided new insights into quantum field theories. Within this framework, photons can be understood as Nambu-Goldstone modes asso…
Enhancement of photon emission rate near QCD critical point
Yukinao Akamatsu, Masayuki Asakawa, Masaru Hongo +2
We compute photon emission rate enhancement near the QCD critical point using an effective theory of dynamic critical phenomena and derive a universal photon spectrum. The emission…
Complex potential and open system applications in heavy-ions and cold atoms
Yukinao Akamatsu
Since the discovery of the complex potential of quarkonium at high temperatures, quarkonium has been regarded as an open quantum system in the quark-gluon plasma. Recently, a simil…
Complex-valued in-medium potential between heavy impurities in ultracold atoms
Yukinao Akamatsu, Shimpei Endo, Keisuke Fujii +1
We formulate the induced potential in a finite temperature cold atomic medium between two heavy impurities, or polarons, which is shown to be \textit{complex-valued} in general. Th…
Drag force near the QCD critical point
Yukinao Akamatsu, Masayuki Asakawa
We discuss how heavy quark dynamics is affected by the critical fluctuations near the QCD critical point at finite temperature and density. We find that the heavy quark momentum di…
Simulation of Lindblad equations for quarkonium in the quark-gluon plasma
Takahiro Miura, Yukinao Akamatsu, Masayuki Asakawa +1
We study the properties of the Lindbladian quantum mechanical evolution of quarkonia with non-Abelian charges (color-singlet and octet) in the quark-gluon plasma. We confirm that h…
Nonequilibrium evolution of quarkonium in medium
Yukinao Akamatsu, Takahiro Miura
We review recent progress in open quantum system approach to the description of quarkonium in the quark-gluon plasma. A particular emphasis is put on the Lindblad equations for qua…
Dynamics of in-medium quarkonia in SU(3) and SU(2) gauge theories
Yukinao Akamatsu, Masayuki Asakawa, Shiori Kajimoto
Decoherence dynamics of quarkonia is studied in the high-temperature deconfined phase of SU() gauge theories. In particular, we analyze the symmetry properties of SU() st…
Quarkonium in Quark-Gluon Plasma: Open Quantum System Approaches Re-examined
Yukinao Akamatsu
Dissociation of quarkonium in quark-gluon plasma (QGP) is a long standing topic in relativistic heavy-ion collisions because it has been believed to signal one of the fundamental n…
Trace preserving quantum dynamics using a novel reparametrization-neutral summation-by-parts difference operator
Oskar Ålund, Yukinao Akamatsu, Fredrik Laurén +3
We develop a novel numerical scheme for the simulation of dissipative quantum dynamics following from two-body Lindblad master equations. All defining continuum properties of the L…
Approach to thermalization and hydrodynamics
Yukinao Akamatsu
I review recent progress in thermalization in heavy-ion collisions, with particular emphasis on hydrodynamic attractor, and also report recent progress in hydrodynamic fluctuations…
Quantum Brownian motion of a heavy quark pair in the quark-gluon plasma
Takahiro Miura, Yukinao Akamatsu, Masayuki Asakawa +1
In this paper we study the real-time evolution of heavy quarkonium in the quark-gluon plasma (QGP) on the basis of the open quantum systems approach. In particular, we shed light o…
Dynamically Integrated Transport Approach for High-Energy Nuclear Collisions at High Baryon Density
Koichi Murase, Yukinao Akamatsu, Masayuki Asakawa +6
To explore the structure of the QCD phase diagram in high baryon density domain, several high-energy nuclear collision experiments in a wide range of beam energies are currently pe…
Transits of the QCD Critical Point
Yukinao Akamatsu, Derek Teaney, Fanglida Yan +1
We analyze the evolution of hydrodynamic fluctuations in a heavy ion collision as the system passes close to the QCD critical point. We introduce two small dimensionless parameters…
Dynamically integrated transport approach for heavy-ion collisions at high baryon density
Yukinao Akamatsu, Masayuki Asakawa, Tetsufumi Hirano +6
We develop a new dynamical model for high energy heavy-ion collisions in the beam energy region of the highest net-baryon densities on the basis of non-equilibrium microscopic tran…
Quantum dissipation of a heavy quark from a nonlinear stochastic Schrödinger equation
Yukinao Akamatsu, Masayuki Asakawa, Shiori Kajimoto +1
We study the open system dynamics of a heavy quark in the quark-gluon plasma using a Lindblad master equation. Applying the quantum state diffusion approach by Gisin and Percival,…
Bulk viscosity from hydrodynamic fluctuations with relativistic hydro-kinetic theory
Yukinao Akamatsu, Aleksas Mazeliauskas, Derek Teaney
Hydro-kinetic theory of thermal fluctuations is applied to a non-conformal relativistic fluid. Solving the hydro-kinetic equations for an isotropically expanding background we find…
A kinetic regime of hydrodynamic fluctuations and long time tails for a Bjorken expansion
Yukinao Akamatsu, Aleksas Mazeliauskas, Derek Teaney
We develop a set of kinetic equations for hydrodynamic fluctuations which are equivalent to nonlinear hydrodynamics with noise. The hydro-kinetic equations can be coupled to existi…
Dynamical dissociation of quarkonia by wave function decoherence
Shiori Kajimoto, Yukinao Akamatsu, Masayuki Asakawa +1
We investigate the real-time evolution of quarkonium bound states in a quark-gluon plasma in one dimension using an improved QCD based stochastic potential model. This model descri…
A new relativistic hydrodynamics code for high-energy heavy-ion collisions
Kazuhisa Okamoto, Yukinao Akamatsu, Chiho Nonaka
We construct a new Godunov type relativistic hydrodynamics code in Milne coordinates, using a Riemann solver based on the two-shock approximation which is stable under the existenc…
A kinetic regime of hydrodynamic fluctuations and long time tails for a Bjorken expansion
Yukinao Akamatsu, Aleksas Mazeliauskas, Derek Teaney
We develop a set of kinetic equations for hydrodynamic fluctuations which are equivalent to nonlinear hydrodynamics with noise. The hydro-kinetic equations can be coupled to existi…
Non-Abelian chiral instabilities at high temperature on the lattice
Yukinao Akamatsu, Alexander Rothkopf, Naoki Yamamoto
We report on an exploratory lattice study on the phenomenon of chiral instabilities in non-Abelian gauge theories at high temperature. It is based on a recently constructed anomalo…
Langevin dynamics and decoherence of heavy quarks at high temperatures
Yukinao Akamatsu
A Langevin equation of heavy quarks in high-temperature quark-gluon plasma is derived. The dynamics of heavy quark color is coupled with the phase space dynamics and causes a macro…