高能暂现源 · 每日文献综述

We study modifications of gravitational wave observables, such as the wave amplitude and frequency, which follow from the quantum equivalence principle, and are expressed in terms of the inertial, gravitational and rest masses of the LIGO/Virgo mirrors. We provide bounds on the violations of the quantum equivalence principle by comparing the results with the most resolved gravitational wave events observed by the LIGO/Virgo collaboration. The formalism is equally applicable to other future ground and space-based gravitational wave detectors.

We propose a mechanism for gravitational wave (GW) production sourced by spectator scalar fields during inflation. These fields, while not driving cosmic expansion, generate blue-tilted isocurvature fluctuations that naturally satisfy current cosmic microwave background (CMB) constraints at large scales while producing enhanced power spectra at smaller scales accessible to GW detectors. The resulting GW spectrum spans an exceptionally broad frequency range from <inline-formula><mml:math><mml:msup><mml:mn>10</mml:mn><mml:mrow><mml:mo>-</mml:mo><mml:mn>20</mml:mn></mml:mrow></mml:msup></mml:math></inline-formula> to 1 Hz, with amplitudes ranging from <inline-formula><mml:math><mml:msub><mml:mi>Ω</mml:mi><mml:mi>GW</mml:mi></mml:msub><mml:msup><mml:mi>h</mml:mi><mml:mn>2</mml:mn></mml:msup><mml:mo>∼</mml:mo><mml:msup><mml:mn>10</mml:mn><mml:mrow><mml:mo>-</mml:mo><mml:mn>19</mml:mn></mml:mrow></mml:msup></mml:math></inline-formula> to <inline-formula><mml:math><mml:msup><mml:mn>10</mml:mn><mml:mrow><mml:mo>-</mml:mo><mml:mn>14</mml:mn></mml:mrow></mml:msup></mml:math></inline-formula> depending on the reheating temperature and spectator field mass. Observable signals across multiple detector bands are possible in a restricted region of parameter space, <inline-formula><mml:math><mml:msub><mml:mi>m</mml:mi><mml:mi>χ</mml:mi></mml:msub><mml:mo>/</mml:mo><mml:msub><mml:mi>H</mml:mi><mml:mi>I</mml:mi></mml:msub></mml:math></inline-formula> within the isocurvature- and <inline-formula><mml:math><mml:mi>∆</mml:mi><mml:msub><mml:mi>N</mml:mi><mml:mi>eff</mml:mi></mml:msub></mml:math></inline-formula>-allowed window and <inline-formula><mml:math><mml:msub><mml:mi>T</mml:mi><mml:mrow><mml:mi>reh</mml:mi></mml:mrow></mml:msub></mml:math></inline-formula>, such that the spectator either provides all of the dark matter (stable case) or decays near matter-radiation equality (unstable case). Our analysis reveals multiple complementary constraints on spectator field parameters. For a high reheating temperature of <inline-formula><mml:math><mml:msub><mml:mi>T</mml:mi><mml:mrow><mml:mi>reh</mml:mi></mml:mrow></mml:msub><mml:mo>&gt;</mml:mo><mml:msup><mml:mn>10</mml:mn><mml:mn>10</mml:mn></mml:msup><mml:mtext> </mml:mtext><mml:mtext> </mml:mtext><mml:mi>GeV</mml:mi></mml:math></inline-formula>, GW-induced limits on the effective number of relativistic species (<inline-formula><mml:math><mml:mi>∆</mml:mi><mml:msub><mml:mi>N</mml:mi><mml:mi>eff</mml:mi></mml:msub></mml:math></inline-formula>) require <inline-formula><mml:math><mml:msub><mml:mi>m</mml:mi><mml:mi>χ</mml:mi></mml:msub><mml:mo>≳</mml:mo><mml:mn>0.59</mml:mn><mml:msub><mml:mi>H</mml:mi><mml:mi>I</mml:mi></mml:msub></mml:math></inline-formula>, stronger than CMB isocurvature bounds alone (<inline-formula><mml:math><mml:msub><mml:mi>m</mml:mi><mml:mi>χ</mml:mi></mml:msub><mml:mo>≳</mml:mo><mml:mn>0.54</mml:mn><mml:msub><mml:mi>H</mml:mi><mml:mi>I</mml:mi></mml:msub></mml:math></inline-formula>). The nonobservation of primordial B-modes by Planck provides stronger constraints, <inline-formula><mml:math><mml:msub><mml:mi>m</mml:mi><mml:mi>χ</mml:mi></mml:msub><mml:mo>≳</mml:mo><mml:mn>0.64</mml:mn><mml:msub><mml:mi>H</mml:mi><mml:mi>I</mml:mi></mml:msub></mml:math></inline-formula>, with projected LiteBIRD sensitivity potentially reaching <inline-formula><mml:math><mml:msub><mml:mi>m</mml:mi><mml:mi>χ</mml:mi></mml:msub><mml:mo>≳</mml:mo><mml:mn>0.67</mml:mn><mml:msub><mml:mi>H</mml:mi><mml:mi>I</mml:mi></mml:msub></mml:math></inline-formula>. This mechanism enables a unique multimessenger probe of beyond the standard model physics during inflation, providing simultaneous constraints on inflationary dynamics, dark matter production, and reheating through current and next-generation GW experiments.