Gravitational wave signatures of dark matter cores in binary neutron star mergers by using numerical simulations

Abstract

Recent detections by the gravitational wave facilities LIGO/Virgo have opened a window to study the internal structure of neutron stars through the gravitational waves emitted during their coalescence. In this work we explore, through numerical simulations, the gravitational radiation produced by the merger of binary neutron stars with dark matter particles trapped on their interior, focusing on distinguishable imprints produced by these dark matter cores. Our results reveal the presence of a strong m = 1 mode in the waveforms during the post-merger stage, together with other relevant features. Comparison of our results with observations might allow us to constraint the amount of dark model in the interior of neutron star.

Testing the nature of dark compact objects: a status report

“…If DM is built out of dark fermions, then formation should parallel that of standard neutron stars, and is also a well understood process. Collisions and merger of compact boson stars [54,415], boson-fermion stars [417,427], and axion stars [420,428] have been studied in detail.…”

“…Unfortunately, predictions for the coalescence in theories other than GR and for objects other that BHs are practically unknown. The exceptions concern evolutions of neutron stars, boson stars, composite fluid systems, and axion stars [54,135,415,417,420,425,427,428] (see Sec. 4.6), and recent progress in BH mergers in modified gravity [522][523][524][525].…”

Dynamical evolution of dark matter admixed neutron stars

“…Measurements of neutron stars could then indirectly probe the properties of dark matter. Dark matter admixed neutron stars are mixtures of the ordinary nuclear matter of a neutron star and dark matter, with dark matter modeled as either a bosonic [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15][16][17][18][19][20] or fermionic particle. In the bosonic case, these systems are more generally known as fermion-boson stars, a name we shall use throughout, reserving dark matter admixed neutron stars for the fermionic case.…”

“…Both systems have been studied extensively at the level of static solutions, which are solutions for which spacetime is time independent. Fermion-boson stars have also been studied dynamically using full numerical relativity [10][11][12][13][14][15][16]. The main purpose of this article is to present for the first time a dynamical study of dark matter admixed neutron stars.…”

Equation of state of strange stars with admissible dark matter: Derivation from galactic rotational curves

“…The first scenario was motivated by the plausible speculation of Bombaci et al (2020) that the gravitational wave signal GW190814 detected in 2019 by the LIGO/Virgo Collaboration (Abbott et al 2019) has been generated by the merger of a binary system whose components are a 23 M ⊙ black hole (BH) and a (2.5 − 2.67) M ⊙ companion compact object, assumed to be a strange star, within the so‐called two‐families scenario in which neutron stars and strange quark stars coexist. The second scenario was motivated by LIGO and Virgo imprints of dark matter particles produced by binary neutron stars mergers and trapped dark matter on the NS interior (Bezares et al 2019).…”