Fast inspirals and the treatment of orbital resonances

Kód výsledku v IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F00216208%3A11320%2F24%3A10491222" target="_blank" >RIV/00216208:11320/24:10491222 - isvavai.cz</a>

Výsledek na webu

<a href="https://verso.is.cuni.cz/pub/verso.fpl?fname=obd_publikace_handle&handle=O-rNWsSP6Q" target="_blank" >https://verso.is.cuni.cz/pub/verso.fpl?fname=obd_publikace_handle&handle=O-rNWsSP6Q</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1088/1361-6382/ad7dc9" target="_blank" >10.1088/1361-6382/ad7dc9</a>

Jazyk výsledku

angličtina

Název v původním jazyce

Fast inspirals and the treatment of orbital resonances

Popis výsledku v původním jazyce

Extreme mass ratio inspirals (EMRIs), where a compact object orbits a massive black hole, are a key source of gravitational waves for the future Laser Interferometer Space Antenna (LISA). Due to their small mass ratio, ( &amp; varepsilon;similar to 10-4-10-7), the binary evolves slowly and EMRI signals will be in-band for years. Additionally, astrophysical EMRIs are expected to have complex dynamics featuring both spin-precession and eccentricity. A standard approach to modelling these inspirals is via the method of osculating geodesics (OG) which we employ along with a toy model for the gravitational self-force. Using this method requires resolving tens of thousands radial and polar orbital librations over the long duration of the signal which makes the inspiral trajectory expensive to compute. In this work we accelerate these calculations by employing Near-Identity (averaging) Transformations. However, this averaging technique breaks down at orbital resonances where the radial and polar frequencies are an integer ratio of each other. Thus, we switch to a partial averaging transformation in the vicinity of the resonance where the dynamics are characterised by the slow evolution of the so-called &apos;resonant phase&apos;. Additionally, we develop an optimal switching criterion to minimise the computation time while maximising accuracy. We find the error in the waveform phase is improved from O(&amp; varepsilon;-1/2) in the fully averaged scheme to O(&amp; varepsilon;4/7) in the switching scheme. At the same time, this scheme improves the scaling of the computation time from being inversely proportional to &amp; varepsilon; using OG, to a very weak scaling with &amp; varepsilon;. This results in a speed-up of at least two orders of magnitude for LISA EMRIs with room for further optimisation.

Název v anglickém jazyce

Fast inspirals and the treatment of orbital resonances

Popis výsledku anglicky

Extreme mass ratio inspirals (EMRIs), where a compact object orbits a massive black hole, are a key source of gravitational waves for the future Laser Interferometer Space Antenna (LISA). Due to their small mass ratio, ( &amp; varepsilon;similar to 10-4-10-7), the binary evolves slowly and EMRI signals will be in-band for years. Additionally, astrophysical EMRIs are expected to have complex dynamics featuring both spin-precession and eccentricity. A standard approach to modelling these inspirals is via the method of osculating geodesics (OG) which we employ along with a toy model for the gravitational self-force. Using this method requires resolving tens of thousands radial and polar orbital librations over the long duration of the signal which makes the inspiral trajectory expensive to compute. In this work we accelerate these calculations by employing Near-Identity (averaging) Transformations. However, this averaging technique breaks down at orbital resonances where the radial and polar frequencies are an integer ratio of each other. Thus, we switch to a partial averaging transformation in the vicinity of the resonance where the dynamics are characterised by the slow evolution of the so-called &apos;resonant phase&apos;. Additionally, we develop an optimal switching criterion to minimise the computation time while maximising accuracy. We find the error in the waveform phase is improved from O(&amp; varepsilon;-1/2) in the fully averaged scheme to O(&amp; varepsilon;4/7) in the switching scheme. At the same time, this scheme improves the scaling of the computation time from being inversely proportional to &amp; varepsilon; using OG, to a very weak scaling with &amp; varepsilon;. This results in a speed-up of at least two orders of magnitude for LISA EMRIs with room for further optimisation.

Druh

J_imp - Článek v periodiku v databázi Web of Science

CEP obor

—

OECD FORD obor

10300 - Physical sciences

Projekt

—

Návaznosti

I - Institucionalni podpora na dlouhodoby koncepcni rozvoj vyzkumne organizace

Rok uplatnění

2024

Kód důvěrnosti údajů

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

Název periodika

Classical and Quantum Gravity

ISSN

0264-9381

e-ISSN

1361-6382

Svazek periodika

41

Číslo periodika v rámci svazku

22

Stát vydavatele periodika

GB - Spojené království Velké Británie a Severního Irska

Počet stran výsledku

46

Strana od-do

225002

Kód UT WoS článku

001331314500001

EID výsledku v databázi Scopus

2-s2.0-85207361829