Reaction-constrained composition g-modes in neutron stars with antikaon condensates, hyperons, and (1232) resonances
Prashant Thakur, Ishfaq Ahmad Rather
astro-ph.HE, nucl-th
Submitted: 2026-07-22
Comments: 20 pages, 9 figures, 8 tables
License: http://creativecommons.org/licenses/by/4.0/
The gist: We study core composition g 1 modes of cold, nonrotating neutron stars containing antikaon condensates, hyperons, and (1232) baryons and present, to our knowledge, the first calculation in full
Terminology
Abstract
We study core composition g 1 modes of cold, nonrotating neutron stars containing antikaon condensates, hyperons, and (1232) baryons and present, to our knowledge, the first calculation in full general relativity of the continuous-composition g 1-mode frequency and gravitational-wave damping time for stars with a K- condensate. Using the BigApple relativistic mean-field equation of state, we compute frequencies, damping times, and frozen-composition tidal overlaps, and identify the buoyancy channels with a species-resolved Ledoux decomposition validated by mode-frequency sensitivities. We compare fully frozen matter with a fast- K limit for n p+K- and a strong-equilibrium limit for the quartet. Fast- K equilibration retains 36% -- 44% of the peak local kaon buoyancy and 65.7% -- 73.4% of the frozen terminal-configuration frequencies, while increasing the damping times by factors of 14.4 -- 31.8; the mode remains above the nucleonic band. Strong equilibration removes most of the direct-induced enhancement, returning the N mode toward the nucleonic band, whereas the high-frequency NY branch survives through the frozen gradient. Eigenfunction tracking confirms a continuous g 1 branch, and representative DD-ME2 calculations reproduce this hierarchy. The direct full-GR frozen-composition phase shifts satisfy g 1 at most1.410 times10-3 rad, a factor of 21 below the 0.03-rad favorable-event scale for the Einstein Telescope. An exotic species therefore produces a distinct composition mode only if its composition gradient, or a coupled slowly equilibrating gradient, survives over the oscillation period.
Sources
- Neutron Star Structure and the Equation of State
- The Equation of State of Hot, Dense Matter and Neutron Stars
- Equations of state for supernovae and compact stars
- GW170817: Observation of Gravitational Waves from a Binary Neutron Star Inspiral
- A NICER View of the Massive Pulsar PSR J0740+6620 Informed by Radio Timing and XMM-Newton Spectroscopy
- The Radius of PSR J0740+6620 from NICER and XMM-Newton Data
- Towards gravitational-wave asteroseismology
- Quasi-Normal Modes of Stars and Black Holes
- Radial and Non-Radial Oscillations of Protoneutron Stars with Hyperonic Composition
- Gravitational Wave asteroseismology revisited
- Asteroseismology of rapidly rotating neutron stars - an alternative approach
- Radial oscillations of relativistic stars
- A gravitational-wave perspective on neutron-star seismology
- Resonant Oscillations and Tidal Heating in Coalescing Binary Neutron Stars
- g-mode Oscillations in Neutron Stars with Hyperons
- Quasi-normal g-modes of neutron stars with quarks
- Asteroseismology of neutron stars with both hyperons and resonances
- The impact of nuclear reactions on the neutron-star g-mode spectrum
- Suppression of composition $g$-modes in chemically-equilibrating warm neutron stars
- The phenomenology of dynamical neutron star tides
Related papers
- Numerical Studies of Accretion Flows onto a Neutron Star Engulfed in a Massive Star
- Collisionless Accretion of Finite-Angular-Momentum Plasma onto a Spinning Black Hole
- Impact of Magnetic Field Topology on Electromagnetic and Gravitational Waves from Binary Neutron Star Merger Remnants
- XRISM Resolve Spectroscopy of GX 5-1: Constraints on Iron Spectral Features in a Luminous Neutron-Star Binary
- SN 1006: A Cosmic Laboratory for Investigating Shock Acceleration Physics
- Neutrino Spectral Pinching in 3D Core-Collapse Supernovae: Late-Time Convergence, Failed-Explosion Signatures, and Viewing-Angle Dispersion