Conical singularity in spacetimes with NUT is observer dependent

Kód výsledku v IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F00216208%3A11320%2F25%3A10506815" target="_blank" >RIV/00216208:11320/25:10506815 - isvavai.cz</a>

Výsledek na webu

<a href="https://verso.is.cuni.cz/pub/verso.fpl?fname=obd_publikace_handle&handle=Re7SmqHOeu" target="_blank" >https://verso.is.cuni.cz/pub/verso.fpl?fname=obd_publikace_handle&handle=Re7SmqHOeu</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1103/w2ct-wjh5" target="_blank" >10.1103/w2ct-wjh5</a>

Jazyk výsledku

angličtina

Název v původním jazyce

Conical singularity in spacetimes with NUT is observer dependent

Popis výsledku v původním jazyce

We discuss the issue of defining and measuring conical deficits (conicity) in spacetimes with the torsion singularity such as the Misner string in Taub-NUT spacetime. We propose a geometric definition that generalizes the standard notion of conicity to stationary axially symmetric spacetimes with torsion singularity, where the conical deficit becomes observer dependent-it depends on the choice of a timelike Killing vector. This implies the existence of observers who perceive no conical singularity along the symmetry axis. As a result, in any spacetime with a nonvanishing NUT parameter, there are observers for whom the conicity has the same value on both semiaxes. This challenges the usual interpretation of conicity differences as indicators of string/rod-induced acceleration along the axis. We illustrate our definition across the full Pleba &amp; nacute;ski-Demia &amp; nacute;ski class, including the recently identified accelerated Taub-NUT solution. Our attempts in determining a canonical observer lead to even less desirable definitions of conicity.

Název v anglickém jazyce

Conical singularity in spacetimes with NUT is observer dependent

Popis výsledku anglicky

We discuss the issue of defining and measuring conical deficits (conicity) in spacetimes with the torsion singularity such as the Misner string in Taub-NUT spacetime. We propose a geometric definition that generalizes the standard notion of conicity to stationary axially symmetric spacetimes with torsion singularity, where the conical deficit becomes observer dependent-it depends on the choice of a timelike Killing vector. This implies the existence of observers who perceive no conical singularity along the symmetry axis. As a result, in any spacetime with a nonvanishing NUT parameter, there are observers for whom the conicity has the same value on both semiaxes. This challenges the usual interpretation of conicity differences as indicators of string/rod-induced acceleration along the axis. We illustrate our definition across the full Pleba &amp; nacute;ski-Demia &amp; nacute;ski class, including the recently identified accelerated Taub-NUT solution. Our attempts in determining a canonical observer lead to even less desirable definitions of conicity.

Druh

J_imp - Článek v periodiku v databázi Web of Science

CEP obor

—

OECD FORD obor

10300 - Physical sciences

Projekt

<a href="/cs/project/GA23-05914S" target="_blank" >GA23-05914S: Pokročilé techniky aplikované na přesné prostoročasy s černými dírami a gravitačními vlnami</a><br>

Návaznosti

P - Projekt vyzkumu a vyvoje financovany z verejnych zdroju (s odkazem do CEP)

Rok uplatnění

2025

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

112

Číslo periodika v rámci svazku

10

Stát vydavatele periodika

US - Spojené státy americké

Počet stran výsledku

18

Strana od-do

104021

Kód UT WoS článku

001619309800002

EID výsledku v databázi Scopus

2-s2.0-105026388932