ترغب بنشر مسار تعليمي؟ اضغط هنا

Ultralight Bosonic Field Mass Bounds from Astrophysical Black Hole Spin

137   0   0.0 ( 0 )
 نشر من قبل Matthew J. Stott
 تاريخ النشر 2020
  مجال البحث فيزياء
والبحث باللغة English
 تأليف Matthew J. Stott




اسأل ChatGPT حول البحث

Black Hole measurements have grown significantly in the new age of gravitation wave astronomy from LIGO observations of binary black hole mergers. As yet unobserved massive ultralight bosonic fields represent one of the most exciting features of Standard Model extensions, capable of providing solutions to numerous paradigmatic issues in particle physics and cosmology. In this work we explore bounds from spinning astrophysical black holes and their angular momentum energy transfer to bosonic condensates which can form surrounding the black hole via superradiant instabilities. Using recent analytical results we perform a simplified analysis with a generous ensemble of black hole parameter measurements where we find superradiance very generally excludes bosonic fields in the mass ranges; spin-0: ${scriptsize { 3.8times10^{-14} {rm eV} leq mu_0 leq 3.4times10^{-11} {rm eV}, 5.5times10^{-20} {rm eV} leq mu_0 leq 1.3times10^{-16} {rm eV}, 2.5times10^{-21} {rm eV} leq mu_0 leq 1.2times10^{-20} {rm eV}}}$, spin-1: ${scriptsize { 6.2times10^{-15} {rm eV} leq mu_1 leq 3.9times10^{-11} {rm eV}, 2.8times10^{-22} {rm eV} leq mu_1 leq 1.9times10^{-16} {rm eV} }}$ and spin-2: ${scriptsize { 2.2times10^{-14} {rm eV} leq mu_2 leq 2.8times10^{-11} {rm eV}, 1.8times10^{-20} {rm eV} leq mu_2 leq 1.8times10^{-16} {rm eV}, 6.4times10^{-22} {rm eV} leq mu_2 leq 7.7times10^{-21} {rm eV} }}$ respectively. We also explore these bounds in the context of specific phenomenological models, specifically the QCD axion, M-theory models and fuzzy dark matter sitting at the edges of current limits. In particular we include recent measurements of event GW190521 and M87* used to constrain both the masses and decay constants of axion like fields. Finally we comment a simple example of a spectrum of fields for the spin-0 and spin-1 cases.



قيم البحث

اقرأ أيضاً

We introduce a statistical method for estimating magnetic field fluctuations generated from primordial black hole (PBH) populations. To that end, we consider monochromatic and extended Press-Schechter PBH mass functions, such that each constituent is capable of producing its own magnetic field due to some given physical mechanism. Assuming linear correlation between magnetic field fluctuations and matter over-densities, our estimates depend on the mass function, the physical field generation mechanism by each PBH constituent, and the characteristic PBH separation. After computing the power spectrum of magnetic field fluctuations, we apply our formalism to study the plausibility that two particular field generation mechanisms could have given rise to the expected seed fields according to current observational constraints. The first mechanism is the Biermann battery and the second one is due to the accretion of magnetic monopoles at PBH formation, constituting magnetic PBHs. Our results show that, for monochromatic distributions, it does not seem to be possible to generate sufficiently intense seed fields in any of the two field generation mechanisms. For extended distributions, it is also not possible to generate the required seed field by only assuming a Biermann battery mechanism. In fact, we report an average seed field by this mechanism of about 10^{-47} G, at z = 20. For the case of magnetic monopoles we instead assume that the seed values from the literature are achieved and calculate the necessary number density of monopoles. In this case we obtain values that are below the upper limits from current constraints.
Starting from the evidence that dark matter indeed exists and permeates the entire cosmos, various bounds on its properties can be estimated. Beginning with the cosmic microwave background and large scale structure, we summarize bounds on the ultrali ght bosonic dark matter (UBDM) mass and cosmic density. These bounds are extended to larger masses by considering galaxy formation and evolution, and the phenomenon of black hole superradiance. We then discuss the formation of different classes of UBDM compact objects including solitons/axion stars and miniclusters. Next, we consider astrophysical constraints on the couplings of UBDM to Standard Model particles, from stellar cooling (production of UBDM) and indirect searches (decays or conversion of UBDM). Throughout, there are short discussions of hints and opportunities in searching for UBDM in each area.
We investigate possible signatures of black hole events at the LHC in the hypothesis that such objects will not evaporate completely, but leave a stable remnant. For the purpose of defining a reference scenario, we have employed the publicly availabl e Monte Carlo generator CHARYBDIS2, in which the remnants behavior is mostly determined by kinematic constraints and conservation of some quantum numbers, such as the baryon charge. Our findings show that electrically neutral remnants are highly favored and a significantly larger amount of missing transverse momentum is to be expected with respect to the case of complete decay.
We examine the real-time dynamics of a system of one or more black holes interacting with long wavelength gravitational fields. We find that the (classical) renormalizability of the effective field theory that describes this system necessitates the i ntroduction of a time dependent mass counterterm, and consequently the mass parameter must be promoted to a dynamical degree of freedom. To track the time evolution of this dynamical mass, we compute the expectation value of the energy-momentum tensor within the in-in formalism, and fix the time dependence by imposing energy-momentum conservation. Mass renormalization induces logarithmic ultraviolet divergences at quadratic order in the gravitational coupling, leading to a new time-dependent renormalization group (RG) equation for the mass parameter. We solve this RG equation and use the result to predict heretofore unknown high order logarithms in the energy distribution of gravitational radiation emitted from the system.
The classical equations of motion for an axion with potential $V(phi)=m_a^2f_a^2 [1-cos (phi/f_a)]$ possess quasi-stable, localized, oscillating solutions, which we refer to as axion stars. We study, for the first time, collapse of axion stars numeri cally using the full non-linear Einstein equations of general relativity and the full non-perturbative cosine potential. We map regions on an axion star stability diagram, parameterized by the initial ADM mass, $M_{rm ADM}$, and axion decay constant, $f_a$. We identify three regions of the parameter space: i) long-lived oscillating axion star solutions, with a base frequency, $m_a$, modulated by self-interactions, ii) collapse to a BH and iii) complete dispersal due to gravitational cooling and interactions. We locate the boundaries of these three regions and an approximate triple point $(M_{rm TP},f_{rm TP})sim (2.4 M_{pl}^2/m_a,0.3 M_{pl})$. For $f_a$ below the triple point BH formation proceeds during winding (in the complex $U(1)$ picture) of the axion field near the dispersal phase. This could prevent astrophysical BH formation from axion stars with $f_all M_{pl}$. For larger $f_agtrsim f_{rm TP}$, BH formation occurs through the stable branch and we estimate the mass ratio of the BH to the stable state at the phase boundary to be $mathcal{O}(1)$ within numerical uncertainty. We discuss the observational relevance of our findings for axion stars as BH seeds, which are supermassive in the case of ultralight axions. For the QCD axion, the typical BH mass formed from axion star collapse is $M_{rm BH}sim 3.4 (f_a/0.6 M_{pl})^{1.2} M_odot$.
التعليقات
جاري جلب التعليقات جاري جلب التعليقات
سجل دخول لتتمكن من متابعة معايير البحث التي قمت باختيارها
mircosoft-partner

هل ترغب بارسال اشعارات عن اخر التحديثات في شمرا-اكاديميا