相关论文: How a cold axion background influences photons

Recent work has shown the utility of examining background effects from ultralight dark matter on precision measurements. This effect enhances seemingly benign contributions to the level that experiments are sensitive to them. In this work,…

A model of Lorentz invariant random fluctuations in photon polarization is presented. The effects are frequency dependent and affect the polarization of photons as they propagate through space. We test for this effect by confronting the…

Primordial electromagnetic fields can strongly affect the cosmic evolution of axions, and vice versa. We show that if helical electromagnetic fields are coherently produced in the early universe, their remnants source a field velocity to…

Photons may convert into axion like particles and back in the magnetic field of various astrophysical objects, including active galaxies, clusters of galaxies, intergalactic space and the Milky Way. This is a potential explanation for the…

We study the problem of axion-photon coupling in the magnetic field influenced by gravitational radiation. We focus on exact solutions to the equations for axion electrodynamics in the pp-wave gravitational background for two models with…

We consider birefringent (i.e., polarization changing) scattering of x-ray photons at the superposition of two optical laser beams of ultra-high intensity and study the resonant contributions of axions or axion-like particles, which could…

We explore a scenario that the dark matter is a boson condensate created by the misalignment mechanism, in which a spin 0 boson (an axion-like particle) and a spin 1 boson (the dark photon) are considered, respectively. We find that…

During its first ~100,000 years, the universe was a fully ionized plasma with a tight coupling by Thompson scattering between the photons and matter. The trade--off between gravitational collapse and photon pressure causes acoustic…

Axion cold dark matter from standard misalignment typically requires a decay constant $f_a~\gtrsim~10^{11}$ GeV. Kinetic misalignment and parametric resonance easily allow lower values of $f_a$ when the radial Peccei-Quinn (PQ) symmetry…

Axions and axion-like particles generically appear in extensions of the Standard Model. While many searches assume only a single axion species, there may exist a whole spectrum of multiple such fields. We develop general formulas for…

Axion-like particles are a well-motivated dark matter candidate that can form a condensate with low momentum and high occupation number. In the presence of dark radiation, this condensate loses energy, naturally increasing the energy…

Ultra-light dark matter may consist of axion-like particles with masses below 10^(-19) eV. Two-photon interactions of these particles affect the polarization of radiation propagating through the dark matter. Coherent oscillations of the…

We posit a second massless photon, uncoupled to known forms of matter but undergoing Lorentz non-invariant velocity mixing with ordinary photons. Our speculation within a speculation suffers from the sin of implausibility but enjoys the…

Recently it has been suggested that dark radiation in the form of axions produced during the decay of string theory moduli fields could be responsible for the soft x-ray excess in galaxy clusters. These soft X-ray photons come about due to…

We compute the probability of photon-axion oscillations in the presence of both intergalactic magnetic fields and an electron plasma and investigate the effect on Type Ia supernovae observations. The conversion probability is calculated…

It is well known that current spectroscopic determinations of the chemical composition of the Sun are starkly at odds with the metallicity implied by helioseismology. We investigate whether the discrepancy may be due to conversion of…

We present a detailed study of the oscillations and optical properties for vacuum, in a model for the dark sector that contains axion-like particles and hidden photons. In this model, both can couple to photons. We provide bounds for the…

Using magnetic white dwarfs as a case study, we show that the emission of sub-MeV bosons from stellar plasmas can be substantially modified in the presence of a magnetic field. In particular, the magnetic field-induced anisotropy and…

Hidden axions may be coupled to the standard model particles through a kinetic or mass mixing with QCD axion. We study a scenario in which a hidden axion constitutes a part of or the whole of dark matter and decays into photons through the…

If there are a plethora of axions in nature, they may have a complicated potential and create an axion landscape. We study a possibility that one of the axions is so light that it is cosmologically stable, explaining the observed dark…