Gravitational Collider Physics via Pulsar-Black Hole Binaries

Ding, Qianhang; Tong, Xi; Wang, Yi

doi:10.48550/arxiv.2009.11106

Cited by 5 publications

(5 citation statements)

References 28 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…It induces the resonant transition to another mode when the orbital frequency coincides with the phase velocity difference between the original mode of the cloud and the other [26,27]. The change of the orbital motion of the binary and the associated GW frequency due to the backreaction can also be a signature of the presence of the cloud [27][28][29][30]. To clarify the impact on the observational signatures, it is important to understand the history of the evolution during the inspiral phase.…”

Section: Introductionmentioning

confidence: 99%

Evolution of binary systems accompanying axion clouds in extreme mass ratio inspirals

Takahashi¹,

Omiya²,

Tanaka³

2023

Preprint

View full text Add to dashboard Cite

Superradiant instability of rotating black holes (BHs) leads to the formation of a cloud of ultralight bosons, such as axions. When the BH with the cloud belongs to a binary system and is in an inspiraling orbit, the resonant transition between the axion's bound states can occur. We study the history of the evolution of the binary system accompanying the cloud composed of the fastest growing mode, and its impact on the observational signatures, especially for small mass ratio cases. In this case, the hyperfine resonance, which has a very small resonance frequency, is relevant. Therefore, due to the long timescale, we should take into account the decaying process of axions in the transition destination mode, the backreaction to the orbital motion and the central BH, and gravitational emission from the cloud. We present a formulation to examine the evolution of the system around the resonance and useful expressions for the analysis. As a result, we found the mass of the cloud that can remain after the resonance is, at most, about 10 −5 of the central BH. The maximum remaining cloud mass is achieved when the mass ratio of the binary is q ∼ 10 −3 . In addition, we show that the resonant transition hardly changes the BH mass and spin distribution, while the associated modification of the gravitational wave frequency evolution when the binary pass through the resonance can be a signature of the presence of the cloud.

show abstract

Section: Introductionmentioning

confidence: 99%

Evolution of binary systems accompanying axion clouds in extreme mass ratio inspirals

Takahashi¹,

Omiya²,

Tanaka³

2023

Preprint

View full text Add to dashboard Cite

show abstract

“…Assuming that this signal is due to a stochastic background of GW, there have been various suggestions for their origin. These include mergers of super-massive black holes [41][42][43] or scenarios involving cosmic string [44][45][46][47], primordial black holes [48][49][50][51][52][53], phase transitions [54][55][56] and magneto-hydrodynamics turbulence during the QCD phase transition [57] and others [58][59][60][61][62][63]. In this work, we focus on the GW spectrum produced in our model of inflationary magnetogenesis where reheating takes place around QCD epoch ( 150 MeV) and compare the predicted signals with those reported by NANOGrav Collaboration.…”

Section: Introductionmentioning

confidence: 99%

Constraining models of inflationary magnetogenesis with NANOGrav data

Sharma

2022

Phys. Rev. D

View full text Add to dashboard Cite

Generation of magnetic field during inflation can explain its presence over a wide range of scales in the Universe. In Ref. [1], we proposed a model to generate these fields during inflation. These fields have nonzero anisotropic stress which lead to the generation of a stochastic background of gravitational waves (GW) in the early universe. Here we show that for a scenario of magnetogenesis where reheating takes place around QCD epoch, this stochastic GW background lies in the 95% confidence region of the GW signal probed by NANOGrav collaboration. This is the case when the generated electromagnetic field (EM) energy density is 3 − 10% of the background energy density at the end of reheating. For this case, the values of magnetic field strength B0 ∼ (3.8 − 6.9) × 10 −11 G and its coherence length ∼ 30 kpc at the present epoch. These values are for the models in which EM fields are of nonhelical nature. For the helical nature of the fields, these values are B0 ∼ (1.1 − 1.9) × 10 −9 G and its coherence length ∼ 0.8 Mpc.

show abstract

“…Thus, the presence of an axion with a corresponding mass excludes highly spinning BHs and predicts a characteristic distribution of the BH mass and spin [19][20][21][22][23]. Other phenomena are the emission of characteristic gravitational waves from the cloud associated with the level transition similar to the photon emission in the hydrogen atom or the pair annihilation of axions [24][25][26][27][28] as well as the modification of the gravitational wave form from binary BHs [29][30][31][32][33][34].…”

Section: Introductionmentioning

confidence: 99%

Adiabatic evolution of the self-interacting axion field around rotating black holes

Omiya,

Takahashi,

Tanaka

2022

Preprint

View full text Add to dashboard Cite

Ultra light axion fields, motivated by the string theory, form a large condensate (axion cloud) around rotating black holes through superradiant instability. Several effects due to the axion cloud, such as the spin-down of black holes and the emission of monochromatic gravitational waves, open a new window to search for axions by astrophysical observations. When the axion self-interaction is considered, the evolution of cloud is altered significantly, and an explosive phenomenon called bosenova can happen. Thus, it is necessary to understand the precise evolution of self-interacting clouds for the detection of axions by astrophysical observations. In this paper, we propose a new method to track the whole process of the growth of self-interacting axion clouds employing the adiabatic approximation. We emphasize that our method relies neither on the nonrelativistic approximation nor on perturbative treatment of the self-interaction, which is often used in literature. Our main finding is that the evolution of cloud in the strongly self-interacting regime depends on the strength of the gravitational coupling between the axion and the black hole. For a large coupling, the cloud evolves into a quasi-stationary state where the superradiant energy gain is balanced with the energy dissipation to infinity by the self-interaction. On the other hand, when one decreases the size of coupling, clouds become unstable at some energy, which would be interpreted as the onset of bosenova.

show abstract

Gravitational Collider Physics via Pulsar-Black Hole Binaries

Cited by 5 publications

References 28 publications

Evolution of binary systems accompanying axion clouds in extreme mass ratio inspirals

Evolution of binary systems accompanying axion clouds in extreme mass ratio inspirals

Constraining models of inflationary magnetogenesis with NANOGrav data

Adiabatic evolution of the self-interacting axion field around rotating black holes

Contact Info

Product

Resources

About