GWX-EOS Seminar
5 events
-
Seminar
Binary neutron Star Merger as a Probe of Hadron-Quark Transition
February 19 (Thu) 14:00 - 15:00, 2026
Yongjia Huang (Research Associate, Purple Mountain Observatory, Chinese Academy of Sciences, China)
This seminar is a joint seminar between GWX-EOS and the iTHEMS-ABBL Joint Astro SG. The recent rise of multi-messenger astronomy—including radius measurements from NICER, tidal deformability constraints from gravitational-wave events GW170817, and first-principles calculations from chiral effective field theory (χEFT) and perturbative QCD—has significantly tightened constraints on the neutron star equation of state. These advances consistently point to a non-monotonic sound speed in dense matter, suggesting that the cores of massive neutron stars may host exotic phases such as quark matter. However, the masquerade effect in static neutron stars makes it difficult to directly probe the nature of the transition (e.g., a smooth crossover or a sharp phase transition) near the core through observation alone.
Venue: #345, 3F, Main Research Building, RIKEN Wako Campus (Main Venue) / via Zoom
Event Official Language: English
-
Seminar
Gyromagnetic Angular Momentum Interconversion in Neutron Stars
August 28 (Thu) 10:00 - 12:00, 2025
Hiroshi Funaki (Specially Appointed Assistant Professor, Faculty of Science and Technology, Keio University)
[NOTE] This informal seminar mainly organized by ABBL will be held in Japanese and is a joint event for GWX-EOS Working Group and iTHEMS-ABBL Joint Astro Study Group. Abstract: We propose a novel mechanism for angular momentum (AM) exchange between the crust and core of a neutron star (NS) via the gyromagnetic effect. Using extended hydrodynamics, we model the star by incorporating macroscopic AM and microscopic AM originating from neutron orbital and spin AM. We reveal that macroscopic dynamics in the crust can inform microscopic AM in the core leading to neutron spin polarization, and offer alternative scenario of (anti-)glitches. This work highlights the overlooked multi-scale AM interconversions in NS physics, paving the way for gyromagnetic astrophysics.
Venue: Hybrid Format (3F #359 and Zoom), Seminar Room #359
Event Official Language: Japanese
-
Seminar
Thermal evolution of accreting neutron stars
July 20 (Sun) 16:00 - 17:30, 2025
Martin Javier Nava-Callejas (Postdoc, Université Libre de Bruxelles, Belgium)
Neutron stars undergoing mass accretion at low-mass X-ray binary systems (LMXBs) represent an outstanding opportunity to test our current models for nuclear matter and its properties, in particular those related to thermonuclear reactions at the surface, as well as the evolution of their ashes via weak reactions. While some aspects are relatively well understood, there are others which call out for further attention or a re-examination of what we so far know. In this talk I will discuss the current state-of-art regarding the modelling of thermal evolution of these objects and will introduce a new method aimed to simplify the calculation of thermal evolution during accreting episodes.
Venue: via Zoom
Event Official Language: English
-
Seminar
Condensed-Matter Physics of Neutron Stars 2
June 25 (Wed) 14:00 - 16:30, 2025
Daisuke Inotani (Postdoctoral Researcher, Research and Education Center for Natural Sciences, Keio University)
Neutron stars, the most compact stars in the Universe, are composed of various matter. However, due to their extremely low temperatures and high densities, they exhibit strong interactions and condensed states. Knowledge of condensed-matter physics is essential for describing such quantum matter. In this lecture, theoretical aspects of condensed-matter physics relevant with neutron stars, through active discussion with participants.
Venue: #359, 3F, RIKEN Wako Campus (Main Venue) / via Zoom
Event Official Language: Japanese
-
Seminar
Condensed-Matter Physics of Neutron Stars 1
June 25 (Wed) 10:00 - 12:30, 2025
Hiroyuki Tajima (Assistant Professor, Graduate School of Science, The University of Tokyo)
Neutron stars, the most compact stars in the Universe, are composed of various matter. However, due to their extremely low temperatures and high densities, they exhibit strong interactions and condensed states. Knowledge of condensed-matter physics is essential for describing such quantum matter. In this lecture, theoretical aspects of condensed-matter physics relevant with neutron stars, through active discussion with participants.
Venue: Seminar Room #359 (Main Venue) / via Zoom
Event Official Language: Japanese
5 events