Spinning test body orbiting around a Kerr black hole: Comparing spin supplementary conditions for circular equatorial orbits

Kód výsledku v IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F67985815%3A_____%2F22%3A00561923" target="_blank" >RIV/67985815:_____/22:00561923 - isvavai.cz</a>

Výsledek na webu

<a href="https://doi.org/10.1103/PhysRevD.106.044039" target="_blank" >https://doi.org/10.1103/PhysRevD.106.044039</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1103/PhysRevD.106.044039" target="_blank" >10.1103/PhysRevD.106.044039</a>

Jazyk výsledku

angličtina

Název v původním jazyce

Spinning test body orbiting around a Kerr black hole: Comparing spin supplementary conditions for circular equatorial orbits

Popis výsledku v původním jazyce

The worldline of a spinning test body moving in curved spacetime can be provided by the Mathisson-Papapetrou-Dixon equations when its centroid, i.e., its center of mass, is fixed by a spin supplementary condition (SSC).nIn the present study, we continue the exploration of shifts between different centroids started in a recently published work [Iason Timogiannis et al., Phys. Rev. D 104, 024042 (2021)., 10.1103/PhysRevD.104.024042], henceforth paper I, for the Schwarzschild spacetime, by examining the frequencies of circular equatorial orbits under a change of the SSC in the Kerr spacetime. In particular, we examine the convergence in the terms of the prograde and retrograde orbital frequencies, when these frequencies are expanded in power series of the spin measure and the centroid of the body is shifted from the Mathisson-Pirani or the Ohashi-Kyrian-Semerák frame to the Tulczyjew-Dixon one. Since in paper I we have seen that the innermost stable circular orbits (ISCOs) hold a special place in this comparison process, we focus on them rigorously in this work. We introduce a novel method of finding ISCOs for any SSC and employ it for the Tulczyjew-Dixon and the Mathisson-Pirani formalisms. We resort to numerical investigation of the convergence between the SSCs for the ISCO case, due to technical difficulties not allowing paper I's analytical treatment. Our conclusion, as in paper I, is that there appears to be a convergence in the power series of the frequencies between the SSCs, which is improved when the proper shifts are taken into account, but there exists a limit in this convergence due to the fact that in the spinning body approximation we consider only the first two lower multipoles of the extended body and ignore all the higher ones.nn

Název v anglickém jazyce

Spinning test body orbiting around a Kerr black hole: Comparing spin supplementary conditions for circular equatorial orbits

Popis výsledku anglicky

The worldline of a spinning test body moving in curved spacetime can be provided by the Mathisson-Papapetrou-Dixon equations when its centroid, i.e., its center of mass, is fixed by a spin supplementary condition (SSC).nIn the present study, we continue the exploration of shifts between different centroids started in a recently published work [Iason Timogiannis et al., Phys. Rev. D 104, 024042 (2021)., 10.1103/PhysRevD.104.024042], henceforth paper I, for the Schwarzschild spacetime, by examining the frequencies of circular equatorial orbits under a change of the SSC in the Kerr spacetime. In particular, we examine the convergence in the terms of the prograde and retrograde orbital frequencies, when these frequencies are expanded in power series of the spin measure and the centroid of the body is shifted from the Mathisson-Pirani or the Ohashi-Kyrian-Semerák frame to the Tulczyjew-Dixon one. Since in paper I we have seen that the innermost stable circular orbits (ISCOs) hold a special place in this comparison process, we focus on them rigorously in this work. We introduce a novel method of finding ISCOs for any SSC and employ it for the Tulczyjew-Dixon and the Mathisson-Pirani formalisms. We resort to numerical investigation of the convergence between the SSCs for the ISCO case, due to technical difficulties not allowing paper I's analytical treatment. Our conclusion, as in paper I, is that there appears to be a convergence in the power series of the frequencies between the SSCs, which is improved when the proper shifts are taken into account, but there exists a limit in this convergence due to the fact that in the spinning body approximation we consider only the first two lower multipoles of the extended body and ignore all the higher ones.nn

Druh

J_imp - Článek v periodiku v databázi Web of Science

CEP obor

—

OECD FORD obor

10308 - Astronomy (including astrophysics,space science)

Projekt

—

Návaznosti

I - Institucionalni podpora na dlouhodoby koncepcni rozvoj vyzkumne organizace

Rok uplatnění

2022

Kód důvěrnosti údajů

S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů

Název periodika

Physical Review D

ISSN

2470-0010

e-ISSN

2470-0029

Svazek periodika

106

Číslo periodika v rámci svazku

4

Stát vydavatele periodika

US - Spojené státy americké

Počet stran výsledku

14

Strana od-do

044039

Kód UT WoS článku

000860618900008

EID výsledku v databázi Scopus

2-s2.0-85136726007