Fundamental-mode eigenfrequencies of neutral and charged twin neutron stars

Victor P. Gonçalves; José C. Jiménez; Lucas Lazzari

doi:10.1140/epjc/s10052-022-11115-0

2022 Impact factor 4.4

Particles and Fields

Open Access

Eur. Phys. J. C (2022) 82: 1117
https://doi.org/10.1140/epjc/s10052-022-11115-0

Regular Article - Theoretical Physics

Fundamental-mode eigenfrequencies of neutral and charged twin neutron stars

Victor P. Gonçalves¹^,2^,3^a, José C. Jiménez⁴ and Lucas Lazzari¹

¹ Institute of Physics and Mathematics, Federal University of Pelotas, Postal Code 354, 96010-900, Pelotas, RS, Brazil
² Institute of Modern Physics, Chinese Academy of Sciences, 730000, Lanzhou, China
³ Institut für Theoretische Physik, Westfälische Wilhelms-Universität Münster, Wilhelm-Klemm-Straße 9, 48149, Münster, Germany
⁴ Instituto de Física, Universidade de São Paulo, Rua do Matão 1371, 05508-090, São Paulo, SP, Brazil

^a barros@ufpel.edu.br

Received: 19 October 2022
Accepted: 5 December 2022
Published online: 10 December 2022

Abstract

We investigate the effects of rapid and slow conversions on the fundamental-mode eigenfrequencies of hybrid neutron stars having highly discontinuous transitions between hadronic and quark matter, the so-called twin stars. We analyze some characteristic cases in the available parameter space of the equations of state for the hadronic and quark phases. Furthermore, we also consider the possibility that these stellar configurations are electrically charged. Our results indicate that for neutral configurations under rapid conversions the stability window coincides with the usual stability criterion, i.e. and that the two branches are disconnected. This discontinuity remains when electric charge is considered, but the usual criterion is not sufficient to determine the star’s stability. On the other hand, slow conversions connect initially disconnected branches and increase the stability window of the hybrid configurations. For both conversion speeds, the presence of electric charge diminishes the magnitude of the eigenfrequencies and its stability window.

© The Author(s) 2022

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