A polarized gamma ray emission spread over a sufficiently wide energy band from a strongly magnetized astrophysical object like gamma ray bursts (GRBs) offers an opportunity to test the hypothesis of axion like particles (ALPs). Based on evidences of polarized gamma ray emission detected in several gamma ray bursts we estimated the level of ALPs induced dichroism, which could take place in the magnetized fireball environment of a GRB. This allows to estimate the sensitivity of polarization measurements of GRBs to the ALP-photon coupling. This sensitivity $\gag\le 2.2\cdot 10^{-11} {\rm GeV^{-1}}$ calculated for the ALP mass $m_a=10^{-3}~{\rm eV}$ and MeV energy spread of gamma ray emission is competitive with the sensitivity of CAST and becomes even stronger for lower ALPs masses.
We point out that the bursts of photons with the energy of the axion mass may appear coincidentally with gamma ray bursts if the gamma ray bursts are caused by collisions between neutron stars and axionic boson stars. In this mechanism, jets are formed in the collisions with large Lorentz factors $\geq 10^2$. We explain qualitatively time-dependent complex structures of gamma ray bursts as well as the large energy problem. Therefore, with detection of the monochromatic photons we can test the model and determine the axion mass.
We propose a model in which ultra high energy cosmic rays and gamma ray bursts are produced by collisions between neutron stars and axion stars. The acceleration of such a cosmic ray is made by the electric field, $\sim 10^{15} (B/10^{12} {G}) {eV} {cm}^{-1}$, which is induced in an axion star by relatively strong magnetic field $B>10^{12}$ G of a neutron star. On the other hand, similar collisions generate gamma ray bursts when magnetic field is relatively small, e.g. $\leq 10^{10}$ G. Assuming that the axion mass is $\sim 10^{-9}$ eV, we can explain huge energies of the gamma ray bursts $\si…
The emission of axions from supernovae is an interesting possibility to account for the Gamma-Ray Bursts provided their energy can be effectively converted into electromagnetic energy elsewhere. The connection between supernova and gamma-ray bursts has been recently confirmed by the observed correlation between the burst of April 25, 1998 and the supernova SN1998bw. We argue that the axion convertion into photons can be more efficient if one considers the coupling between an intermediate scale axion and the string theory dilaton along with the inclusion of string loops. We also discuss the way…
A modification of the relation between axion mass and the PQ constant permits a relaxation of the astrophysical constraints, considerably enlarging the allowed axion parameter space. We develop this idea in this paper, discussing a model for an {\it ultramassive} axion, which essentially represents a supersymmetric Weinberg-Wilczek axion of the mirror world. The experimental and astrophysical limits allow a PQ scale f_a ~ 10^4-10^6 GeV and a mass m_a ~ 1MeV, which can be accessible for future experiments. On a phenomenological ground, such an {\it ultramassive} axion turns out to be quite inte…
We indicate a possible mechanism of generating gamma ray bursts. They are generated by a collision between an axionic boson star and a neutron star. The axionic boson star can dissipates its whole energy $10^{50}$ erg in the magnetized conducting medium of the neutron star. This dissipation arises only around envelope of the neutron star so that a fire ball with small baryon contamination is expected. We have evaluated roughly a rate of the collision per year and per galaxy which is consistent with observations, under plausible assumptions. We also point out that cosmic rays with extremely hig…
We show that fast radio bursts arise from collisions between axion stars and neutron stars. The bursts are emitted in the atmosphere of the neutron stars. The observed frequencies of the bursts are given by the axion mass $m_a$ such as $m_a/2π\simeq 1.4\,\mbox{GHz}\,\big(m_a/(6\times 10^{-6}\mbox{eV})\big)$. From the event rate $\sim 10^{-3}$ per year in a galaxy, we can determine the mass $\sim 10^{-11}M_{\odot}$ of the axion stars. Using these values we can explain short durations ( $\sim $ms ) and amount of radiation energies ( $\sim 10^{43}$GeV ) of the bursts.
We study the radio signals generated when an axion star enters the magnetosphere of a neutron star. As the axion star moves through the resonant region where the plasma-induced photon mass becomes equal to the axion mass, the axions can efficiently convert into photons, giving rise to an intense, transient radio signal. We show that a dense axion star with a mass $\sim 10^{-13}M_{\odot}$ composed of $\sim 10\: μ$eV axions can account for most of the mysterious fast radio bursts.
Axions may make a significant contribution to the dark matter of the universe. It has been suggested that these dark matter axions may condense into localized clumps, called "axion stars." In this paper we argue that collisions of dilute axion stars with neutron stars, of the type known as "magnetars," may be the origin of most of the observed fast radio bursts. This idea is a variation of an idea originally proposed by Iwazaki. However, instead of the surface effect of Iwazaki, we propose a perhaps stronger volume effect caused by the induced time dependent electric dipole moment of neutrons.
The axion objects such as axion mini-clusters and axion clouds around spinning black holes induce parametric resonances of electromagnetic waves through the axion-photon interaction. In particular, it has been known that the resonances from the axion with the mass around $10^{-6}$eV may explain the observed fast radio bursts (FRBs). Here we argue that similar bursts of high frequency gravitational waves, which we call the fast gravitational wave bursts (FGBs), are generated from axion clumps with the presence of gravitational Chern-Simons (CS) coupling. The typical frequency is half of the axi…
Emission of relativistic axions from transient sources, such as axion star explosions, can lead to observable signatures. We show that axion bursts from collapsing axion stars can be detectable over the wide range of axion masses $10^{-15} \, \textrm{eV} \lesssim m \lesssim 10^{-7} \, \textrm{eV}$ in laboratory experiments, such as ABRACADABRA, DMRadio and SHAFT. The detection of axion bursts could provide new insights into the fundamental axion potential, which is challenging to probe otherwise. An ensemble of bursts in the distant past would give rise to a diffuse axion background distinct f…
We re-examine the possibility of an astrophysically allowed KSVZ-type axion that has a strongly suppressed coupling to photons. We then investigate the impact of such ''hadronic axions'' on two classes of astrophysical objects: black hole accretion disc (BHAD) based gamma-ray bursts and isolated neutron-stars. Although our results are sensitive to details of the underlying models, we show that hadronic axions could in principle play an important role in the evolution of gamma-ray bursts and in the cooling behaviour of neutron stars.
A polarized gamma ray emission spread over a sufficiently wide energy band from a strongly magnetized astrophysical object like gamma ray bursts (GRBs) offers an opportunity to test the hypothesis of invisible axion. The axionic induced dichroism of gamma rays at different energies should cause a misalignment of the polarization plane for higher energy events relative to that one for lower energies events resulting in the loss of statistics needed to form a pattern of the polarization signal to be recognized in a detector. According to this, any evidence of polarized gamma rays coming from an …
Axion is a promising candidate of dark matter in the universe. A fraction of dark matter axion may forms axion star with radius $\sim 10^2$km. We show that the axion star emits radiation burst by the collision with K and M types main sequence star in the Andromeda Galaxy. The emission arises in the atmosphere of the star, in which electrons coherently oscillate due to oscillating electric field of the axion star. The electric field is produced under magnetic field $B$ of the star. We estimate the flux density of the radiation $\sim 1.6\times 10^{-3}\mbox{Jy} (10^{-12}M_{\odot}/M_a)^2(10^{-5}\m…
The Pseudo-Goldstone Boson (PGB) emission could provide a very efficient mechanism for explaining the cosmic Gamma Ray Bursts (GRBs). The PGBs could be produced during the merging of two compact objects like two neutron stars or neutron star - black hole, and then decay into electron-positron pairs and photons at distances ~ 100-1000 km. In this way, a huge energy (up to more than 10^{54} erg) can be deposited into the outer space with low baryon density in the form of ultrarelativistic e^+e^- plasma, the so called fireball, which originates the observed gamma-ray bursts. The needed ranges for…
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 stars or during their collapse. In this short research note an importance of three observational criteria is outlined, namely total energetic, $\mathcal{O}$(ms) duration and non-monochromatic shape of the spectrum. It is shown that it is impossible to meet these criteria in simplified models of axion-neutron star interaction scenario and thorough investigati…
Telescope Array (TA) experiment has recorded \cite{Abbasi:2017rvx,Okuda_2019} several short time bursts of air shower like events. These bursts are very distinct from conventional single showers, and are found to be strongly correlated with lightnings. In our previous work \cite{Zhitnitsky:2020shd} we proposed that these bursts represent the direct manifestation of the dark matter (DM) annihilation events within the so-called axion quark nugget (AQN) model. In the present work we suggest to test this proposal to search for the radio signals in frequency band $ν\in (0.5-200)$ MHz which must be …
We investigate the bursts of electromagnetic and scalar radiation resulting from the collision, and merger of oscillons made from axion-like particles using 3+1 dimensional lattice simulations of the coupled axion-gauge field system. The radiation into photons is suppressed before the merger. However, it becomes the dominant source of energy loss after the merger if a resonance condition is satisfied. Conversely, the radiation in scalar waves is dominant during initial merger phase but suppressed after the merger. The backreaction of scalar and electromagnetic radiation is included in our simu…
Axions are one of the most promising candidates of dark matter. The axions have been shown to form miniclusters with masses $\sim 10^{-12}M_{\odot}$ and to become dominant component of dark matter. Some of the axion miniclusters condense to form axion stars. We have recently shown a possible origin of fast radio bursts ( FRBs ) by assuming that the axion stars are main component of halos: FRBs arise from the collisions between the axion stars and neutron stars. It is remarkable that the masses of the axion stars obtained by the comparison of the theoretical and observational event rates are co…
We have proposed a model of non repeating fast radio bursts ( FRBs ); the collisions between axion stars and neutron stars generate the bursts. In this paper, we propose a model of repeating FRBs which shows that they arise from the several collisions between magnetized accretion disk of a black hole and an axion star orbiting the black hole. There would be many axions stars condensing as dark matter in an early stage galaxy so that such collisions arises repeatedly. The radiations are emitted by coherent oscillations of electrons in the accretion disk. The oscillations are caused by oscillati…
We explore the possibility that the Fast Radio Bursts (FRBs) are powered by magnetic reconnection in magnetars, triggered by Axion Quark Nugget (AQN) dark matter. In this model, the magnetic reconnection is ignited by the shock wave which develops when the nuggets' Mach number $M \gg 1$. These shock waves generate very strong and very short impulses expressed in terms of pressure $Δp/p\sim M^2$ and temperature $ΔT/T\sim M^2$ in the vicinity of (would be) magnetic reconnection area. We find that the proposed mechanism produces a coherent emission which is consistent with current data, in partic…
Telescope Array (TA) experiment has recorded \cite{Abbasi:2017rvx,Okuda_2019} several short time bursts of air shower like events. These bursts are very distinct from conventional single showers, and are found to be strongly correlated with lightnings. We propose that these bursts represent the direct manifestation of the dark matter annihilation events within the so-called axion quark nugget (AQN) model, which was originally invented for completely different purpose to explain the observed similarity between the dark and the visible components in the Universe, i.e. $Ω_{\rm DM}\sim Ω_{\rm visi…
During a core-collapse supernova (SN), axion-like particles (ALPs) could be produced through the Primakoff process and subsequently convert into gamma rays in the magnetic field of the Milky Way. Using a sample of well studied extragalactic SNe at optical wavelengths, we estimate the time of the core collapse and search for a coincident gamma-ray burst with the Fermi Large Area Telescope (LAT). Under the assumption that at least one SN was contained within the LAT field of view, we exclude photon-ALP couplings within a factor of $\sim$5 of previous limits from SN1987A. With the increasing numb…
Detecting Extragalactic Axion-like Dark Matter with Polarization Measurements of Fast Radio Bursts
Purple Mountain Observatory, Chinese Academy of Sciences（中国科学院紫金山天文台）；School of Astronomy and Space Sciences, University of Science and Technology of China（中国科学技术大学天文与空间科学学院）
We consider the problem of axion production by bremsstrahlung emission in a nuclear medium. The usual assumption of a massless axion is replaced by more general hypotheses, so that we can describe the emission process for axions with mass up to a few MeV. We point out that in certain physical situations the contribution from non-zero mass is non-negligible. In particular, in the mechanism for the production of Gamma Ray Bursts via emission of heavy axions the axion mass m_a ~ 1MeV is comparable with the temperature of the nuclear medium and thus can not be disregarded. Looking at our results w…
We propose a model in which ultra high energy cosmic rays are produced by collisions between neutron stars and axion stars. The acceleration of such a cosmic ray is made by the electric field, $\sim 10^{15} (B/10^{12} {G}) {eV} {cm}^{-1}$, which is induced in an axion star by the strong magnetic field $B>10^{12}$ G of a neutron star. As we have shown previously, similar collisions generate gamma ray bursts when the magnetic field is much smaller, e.g. $\sim 10^{10}$ G. If we assume that the axion mass is $\sim 10^{-9}$ eV, we can explain huge energies of the gamma ray bursts $\sim 10^{54}$ erg…
Photons couple to Axion-Like Particles (ALPs) or more generally to any pseudo Nambu-Goldstone boson in the presence of an external electromagnetic field. Mixing between photons and ALPs in the strong magnetic field of a Gamma-Ray Burst (GRB) jet during the prompt emission phase can leave observable imprints on the gamma-ray polarization and spectrum. Mixing in the intergalactic medium is not expected to modify these signatures for ALP mass > 10^(-14) eV and/or for < nG magnetic field. We show that the depletion of photons due to conversion to ALPs changes the linear degree of polarization from…
The coupling between a pseudo-scalar inflaton and a gauge field leads to an amount of additional density perturbations and gravitational waves (GWs) that is strongly sensitive to the inflaton speed. This naturally results in enhanced GWs at (relatively) small scales that exited the horizon well after the CMB ones, and that can be probed by a variety of GW observatories (from pulsar timing arrays, to astrometry, to space-borne and ground-based interferometers). This production occurs in a regime in which the gauge field significantly backreacts on the inflaton motion. Contrary to earlier assump…
The fast radio bursts ( FRBs ) are energetic radio bursts with millisecond duration only observed at radio frequencies. The generation mechanism is still mysterious. We have proposed a generation mechanism of both repeating and one-off FRBs. They arise from the axion star collision with neutron star or magnetized accretion disk of galactic black hole. Once we accept the existence of the axions, we find that the mechanism well explain previously observed spectral-temporal features. In this paper we show that it also explains recently observed phenomena such as downward drifting in the repeating…
Axion emission by hot and dense plasmas is a new energy-loss channel for stars. Observational consequences include a modification of the solar sound-speed profile, an increase of the solar neutrino flux, a reduction of the helium-burning lifetime of globular-cluster stars, accelerated white-dwarf cooling, and a reduction of the supernova SN 1987A neutrino burst duration. We review and update these arguments and summarize the resulting axion constraints.
We show that axionic boson stars collide with isolated old neutron stars with strong magnetic field ($>10^8$ Gauss) and causes the neutron stars to radiate X ray by heating them. Surface temperatures of such neutron stars becomes$10^5 K \sim 10^6 K$. We suggest that these are possible candidates for X ray sources observed in ROSAT Survey. We discuss a possible way of identifying such neutron stars. We also point out that the collision generates a burst of monochromatic radiations with frequency given by axion mass.
The strongest upper bounds on the axion mass come from astrophysical observations like the neutrino burst duration of SN1987A, which depends on the axion couplings to nucleons, or the white-dwarf cooling rates and red-giant evolution, which involve the axion-electron coupling. It has been recently argued that in variants of DFSZ models with generation-dependent Peccei-Quinn charges an approximate axion-nucleon decoupling can occur, strongly relaxing the SN1987A bound. However, as in standard DFSZ models, the axion remains in general coupled to electrons, unless an ad hoc cancellation is engine…
Experimental observations indicate that gamma-ray bursts (GRB) and high-energy neutrino bursts may travel at different speeds with a typical delay measured at the order of hours or days. We discuss two potential interpretations for the GRB delay: dispersion of light in interstellar medium and violation of Lorentz invariance due to quantum gravitational fluctuations. Among a few other media, we consider dispersion of light in an axion plasma, obtaining the axion plasma frequency and the dispersion relation from quantum field theory for the first time. We find that the density of axions inferred…
Reappraisal of the Constraints on Heavy Axion-like Particles from Gamma-Ray Bursts
Washington University（华盛顿大学）；Johannes Gutenberg-Universität Mainz（美因茨约翰内斯古腾堡大学）；SISSA, International School for Advanced Studies（国际高等研究学院）；IFPU, Institute for Fundamental Physics of the Universe（宇宙基础物理研究所）；INFN, Sezione di Trieste（意大利国家核物理研究所的里雅斯特分部）；University of Johannesburg（约翰内斯堡大学）；The George Washington University（乔治华盛顿大学）
We revisit the limit on very light axion-like particles (ALPs) from the absence of gamma rays coincidental with the neutrino burst from SN1987A. We use updated supernova simulations, modern models for the magnetic field inside the Galaxy, and a Primakoff cross section which takes into account proton-degeneracy and mass-reduction effects. We finally give an updated exclusion plot for the electromagnetic coupling of sub-eV ALPs, comparing our new bound with other limits as well as with future ALP searches.
Constraints on Axion-like Dark Matter from Cosmic Birefringence with a Polarization Array of Repeating Fast Radio Bursts
State Key Laboratory of Radio Astronomy and Technology, National Astronomical Observatories, CAS（中国科学院国家天文台射电天文与技术重点实验室）；School of Astronomy and Space Science, University of Chinese Academy of Sciences（中国科学院大学天文与空间科学学院）；Asia Pacific Center for Theoretical Physics (APCTP)（亚太理论物理中心）；National Astronomical Observatories, Chinese Academy of Sciences（中国科学院国家天文台）；Department of Astronomy, School of Physics and Materials Science, Guangzhou University（广州大学物理与材料科学系天文学系）
We determine limits from SN 1987A on massive axion-like particles (ALPs) with masses in the 10 keV - 100 MeV range and purely coupled to two photons. ALPs produced in the core collapse escape from the star and decay into photons that can be observed as a delayed and diffuse burst. We discuss the time and angular distribution of such a signal. Looking into the future we also estimate the possible improvements if the red supergiant Betelgeuse explodes in a supernova event.
The Large High Altitude Air Shower Observatory (LHAASO) has reported the detection of a large number of multi-TeV-scale photon events including also several PeV-scale gamma-ray-photon events with energy as high as 1.4 PeV. The possibility that some of these events may have extragalactic origins is not yet excluded. Here we propose a mechanism for the traveling of very-high-energy (VHE) and ultra-high-energy (UHE) photons based upon the axion-photon conversion scenario, which allows extragalactic above-threshold photons to be detected by observers on the Earth. We show that the axion-photon con…
Recent astrophysical transient Swift J1913.1+1946 is possibly associated with the gamma-ray burst GRB 221009A at the redshift z=0.151. The transient was accompanied by very high-energy gamma rays up to 18 TeV observed by LHAASO and a photon-like air shower of 251 TeV detected by Carpet-2. These energetic gamma rays cannot reach us from the claimed distance of the source because of the pair production on cosmic background radiation. If the identification and redshift measurements are correct, one would require new physics to explain the data. One possibility invokes axion-like particles (ALPs) …
During a core-collapse supernova (SN), axionlike particles (ALPs) could be produced through the Primakoff process and subsequently convert into $γ$ rays in the magnetic field of the Milky Way. We do not find evidence for such a $γ$-ray burst in observations of extragalactic SNe with the Fermi Large Area Telescope (LAT). The SN explosion times are estimated from optical light curves and we find a probability of about $\sim$90% that the LAT observed at least one SN at the time of the core collapse. Under the assumption that at least one SN was contained within the LAT field of view, we exclude p…
Testing new-physics scenarios with the combined LHAASO and Carpet-3 fluence spectrum of GRB 221009A: axion-like particles and Lorentz-invariance violation
Institute for Nuclear Research of the Russian Academy of Sciences（俄罗斯科学院核物理研究所）；Faculty of Physics, Lomonosov Moscow State University（莫斯科国立大学物理系）
Various satellite-borne missions are being planned whose goal is to measure the polarization of a large number of gamma-ray bursts (GRBs). We show that the polarization pattern predicted by current models of GRB emission can be drastically modified by the existence of very light axion-like particles (ALPs), which are present in many extensions of the Standard Model of particle physics. Basically, the propagation of photons emitted by a GRB through cosmic magnetic fields with a domain-like structure induces photon-ALP mixing, which is expected to produce a strong modification of the original ph…
Axion-like particles (ALPs) and photons can quantum mechanically interconvert when propagating through magnetic fields, and ALP-photon conversion may induce oscillatory features in the spectra of astrophysical sources. We use deep (370 ks), short frame time Chandra observations of the bright nucleus at the centre of the radio galaxy M87 in the Virgo cluster to search for signatures of light ALPs. The absence of substantial irregularities in the X-ray power-law spectrum leads to a new upper limit on the photon-ALP coupling, $g_{aγ}$: using a conservative model of the cluster magnetic field cons…
Motivated by some of the recent swampland conjectures, we study the implementation for the late time acceleration of the Universe of a mechanism developed by Anber and Sorbo in the context of primordial inflation, in which an axion field can slowly roll in a steep potential due to additional friction provided by its coupling to some U(1) gauge field. We first study the realization of this mechanism in N = 2 supergravity models resulting from string compactifications on Calabi--Yau manifolds. We then study the transition between matter domination and the axion domination, and show that indeed t…
