Related papers: Astrophysical Axion Bounds
The high-energy Universe is potentially a great laboratory for searching new light bosons such as axion-like particles (ALPs). Cosmic sources are indeed the scene of violent phenomena that involve strong magnetic field and/or very long…
The high temperature and electron degeneracy attained during a supernova allow for the formation of a large muon abundance within the core of the resulting proto-neutron star. If new pseudoscalar degrees of freedom have large couplings to…
We calculate limits on the properties of neutrinos using data from gamma-ray detectors on the Pioneer Venus Orbiter and Solar Max Mission satellites. A massive neutrino decaying in flight from the supernova would produce gamma rays…
We apply new upper limits on neutrino fluxes and the diffuse extragalactic component of the GeV gamma-ray flux to various scenarios for ultra high energy cosmic rays and neutrinos. As a result we find that extra-galactic top-down sources…
Fast radio bursts can be caused by some phenomena related to 'new physics'.One of the most prominent candidates of the kind are axion Bose stars which can engender bursts when undergoing conversion into photons in magnetospheres of neutron…
Following Ruffini and Bonazzola, we use a quantized boson field to describe condensates of axions forming compact objects. Without substantial modifications, the method can only be applied to axions with decay constant, $f_a$, satisfying…
We examine the constraints on soft X-ray emissions from the reionization era. It has generally been assumed that the Universe was reionized by ultraviolet photons from massive stars. However, it has been argued that X-ray photons associated…
We show how the properties of the QCD axion change in systems at finite baryonic density, such as neutron stars. At nuclear saturation densities, where corrections can be reliably computed, we find a mild reduction of the axion mass and up…
In this paper, we evaluate the energy loss rate of supernovae induced by the axion emission process $\pi^- + p \to n + a$ with the $\Delta(1232)$ resonance in the heavy baryon chiral perturbation theory for the first time. Given the…
The structure of static atmospheres around unmagnetized neutron stars undergoing steady, spherical accretion is discussed. We focus on the ``hot'' configurations presented by Turolla et al. (1994) and calculate the radiation spectrum using…
Contemporary attempts to explain the existence of ultra-high energy cosmic rays using plasma-based wakefield acceleration deliberately avoid non-Standard Model particle physics. However, such proposals exploit some of the most extreme…
Neutron stars such as pulsars and magnetars lose angular momentum primarily through electromagnetic dipole radiation, gravitational waves, $r$-mode oscillation, and also affected by fallback accretion processes. However, anomalous spin…
Axions, and axion-like particles, have come back into fashion in the last decades as a possible solution to the galactic-scale crisis suffered by the cold dark matter model. In the framework of the wave Dark Matter model, we have carried…
The cumulative emission of Axion-Like Particles (ALPs) from all past core-collapse supernovae (SNe) would lead to a diffuse flux with energies ${\mathcal O}(50)$ MeV. We use this to constrain ALPs featuring couplings to photons and to…
We present a systematic study of QCD axion production in environments with finite baryon density and temperature, implying significant changes to axion phenomenology. Within heavy baryon chiral perturbation theory, we derive the effective…
We explore the dynamics of boson stars in the presence of axionic couplings through nonlinear evolutions of Einstein's field equations. We show that, for large axionic couplings, isolated boson stars become unstable, and decay via a large…
We review the wide range of astrophysical observations of gamma ray emission lines and we discuss their implications. We consider line emission from solar flares, the Orion molecular cloud complex, supernovae 1987A and 1991T, the supernova…
The system of neutrino-antineutrino $(\nu\bar{\nu})$ - plasma is considered taking into account their weak Fermi interaction. New fluid instabilities driven by strong neutrino flux in a plasma are found. The nonlinear stationary as well as…
Axions are possible candidates of dark matter in the present Universe. They have been argued to form axionic boson stars with small masses $\sim 10^{-12}M_{\odot}$. Since they possess oscillating electric fields in a magnetic field, they…
Core-collapse supernovae provide natural laboratories for the production of new light particles. In particular, axion-like particles (ALPs) can be constrained via SN1987A cooling arguments. However, significant astrophysical and nuclear…