Accessing the axion via compact object binaries
Accessing the axion via compact object binaries
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DOI：
10.1088/1475-7516/2020/08/005
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发表时间：
2019-10
影响因子：
6.4
通讯作者：
Michael Kavic;S. Liebling;M. Lippert;J. Simonetti
中科院分区：
文献类型：
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作者：
Michael Kavic;S. Liebling;M. Lippert;J. Simonetti
与其他致密物体一起形成双星的黑洞可以为间接探测轴子或其他超轻场提供自然的场所。与快速旋转的黑洞相关的超辐射不稳定性导致了轴子云的产生，轴子云携带着来自黑洞的能量和角动量。然后，这个云将通过引力波发射而衰变。我们表明，由于这一过程中的能量损失往往朝着一个outspiraling的双轨道。一个给定的双星系统对一个狭窄的轴子质量范围很敏感，这个范围由黑洞的质量决定。这一提议为其他探测或约束超辐射产生的光粒子的方法提供了一种补充选择，例如直接测量黑洞自旋或探测由此产生的引力波信号。脉冲星-黑洞双星一旦在电磁波段被探测到，将允许通过对伴星脉冲星的定时测量来高精度地测量黑洞质量损失。鉴于LIGO/Virgo最近初步宣布的两个候选黑洞-中子星星合并（#S190814bv和#S190426c），这种调查途径特别有希望。我们证明，对于这样一个由一个典型的毫秒脉冲星和一个3 M的黑洞组成的双星系统，质量在2.7 × 10−12 eV和3.2 × 10−12 eV之间的轴子是可以探测到的。最近LIGO/Virgo对双星黑洞合并的引力波观测表明，对于这些双星，来自旋转四极矩的引力辐射是一个主导效应，导致了一个螺旋轨道。通过对双星形成时的周期和黑洞自旋的合理假设，这些观测排除了轴子质量在3 × 10−13 eV到6 × 10−13 eV之间的可能性。未来的双黑洞观测，例如丽莎，预计将提供更强大的界限。在某些情况下，中子星也可能经历超辐射不稳定性，而双星可以用来排除具有一定质量和物质耦合的轴子。
Black holes in binaries with other compact objects can provide natural venues for indirect detection of axions or other ultralight fields. The superradiant instability associated with a rapidly spinning black hole leads to the creation of an axion cloud which carries energy and angular momentum from the black hole. This cloud will then decay via gravitational wave emission. We show that the energy lost as a result of this process tends toward an outspiraling of the binary orbit. A given binary system is sensitive to a narrow range of axion masses, determined by the mass of the black hole. This proposal provides a complementary alternative to other approaches for detecting or constraining light particles created by superradiance, such as directly measuring the black hole spin or detecting the resulting gravitational wave signal. Pulsar-black hole binaries, once detected in the electromagnetic band, will allow high-precision measurements of black hole mass loss via timing measurements of the companion pulsar. This avenue of investigation is particularly promising in light of the recent preliminary announcements of two candidate black hole-neutron star mergers by LIGO/Virgo (#S190814bv and #S190426c). We demonstrate that for such a binary system with a typical millisecond pulsar and a 3M⊙ black hole, axions with masses between 2.7 × 10−12 eV and 3.2 × 10−12 eV are detectable. Recent gravitational wave observations by LIGO/Virgo of binary black hole mergers imply that, for these binaries, gravitational radiation from the rotating quadrupole moment is a dominant effect, causing an inspiraling orbit. With some reasonable assumptions about the period of the binary when it formed and the spins of the black holes, these observations rule out possible axion masses between 3 × 10−13 eV and 6 × 10−13 eV . Future binary black hole observations, for example by LISA, are expected to provide more robust bounds. In some circumstances, neutron stars may also undergo superradiant instabilities, and binary pulsars could be used to exclude axions with certain masses and matter couplings.