Feebly Interacting Massive Particles (FIMPs) are dark matter candidates that never thermalize in the early universe and whose production takes place via decays and/or scatterings of thermal bath particles. If FIMPs interactions with renormalizable, a scenario which is known as freeze-in, most efficient at temperatures around mass particles insensitive to unknown physics high temperatures. Working model-independent fashion, we consider three different mechanisms: two-body decays, three-body...

The axion-gluon coupling is the defining feature of QCD axion. This induces additional and qualitatively different interactions axion with standard model particles—quadratic couplings. Previously, hadronic quadratic couplings have been studied experimental implications explored especially in context atomic spectroscopy interferometry. We investigate to electromagnetic field electron mass. These are generated at loop level from threshold corrections expected be present absence fine-tuning....

The adiabatic growth of a central massive black hole could compress the surrounding dark matter halo, leading to steeper profile halo. This phenomenon is called compression. We investigate compression wave matter---a light bosonic candidate with its mass smaller than few eV. Using theorem, we show that leads much denser halo similar particle in semiclassical limit. compressed differs from near center where approximation breaks down, and depends on as they determine whether soliton low...

A massive astrophysical object deforms a local distribution of dark matter, resulting in overdensity matter. This phenomenon is often referred to as gravitational focusing. In the solar system, focusing due Sun induces modulations matter signals on terrestrial experiments. We consider light bosonic with mass less than about 10 eV. The wave nature such candidates leads unique signatures both and spectrum, which can be experimentally relevant. provide formalism that captures stochasticity...

Abstract Motivated by the stunning projections for future CMB surveys, we evaluate amount of dark radiation produced in early Universe two-body decays or binary scatterings with thermal bath particles via a rigorous analysis momentum space. We track evolution phase space distribution, and use asymptotic solution to additional relativistic energy density parameterized terms an effective number neutrino species Δ N eff . Our approach allows studying light that never reach equilibrium across...

We investigate the cosmological consequences of axion interactions with standard model fermions accurately and precisely. Our analysis is entirely based on a phase space framework that allows us to keep track distribution in momentum across entire expansion history. First, we consider flavor-diagonal couplings charged leptons quantify expected amount dark radiation as function coupling strength. Leptophilic axions are immune from complications due strong our predictions do not suffer...

We investigate the cosmological consequences of axion interactions with standard model fermions accurately and precisely. Our analysis is entirely based on a phase space framework that allows us to keep track distribution in momentum across entire expansion history. First, we consider flavor-diagonal couplings charged leptons quantify expected amount dark radiation as function coupling strength. Leptophilic axions are immune from complications due strong our predictions do not suffer...

The axion-gluon coupling is the defining feature of QCD axion. This induces additional and qualitatively different interactions axion with standard model particles -- quadratic couplings. Previously, hadronic couplings have been studied experimental implications explored especially in context atomic spectroscopy interferometry. We investigate to electromagnetic field electron mass. These are generated at loop level from threshold corrections expected be present absence fine-tuning. While...

Motivated by the stunning projections for future CMB surveys, we evaluate amount of dark radiation produced in early Universe two-body decays or binary scatterings with thermal bath particles via a rigorous analysis momentum space. We track evolution phase space distribution, and use asymptotic solution to additional relativistic energy density parameterized terms an effective number neutrino species $ΔN_{\rm eff}$. Our approach allows studying light that never reach equilibrium across...

The adiabatic growth of a central massive black hole could compress the surrounding dark matter halo, leading to steeper profile halo. This phenomenon is called compression. We investigate compression wave - light bosonic candidate with its mass smaller than few eV. Using theorem, we show that leads much denser halo similar particle in semiclassical limit. compressed differs from near center where approximation breaks down, and depends on as they determine whether soliton low angular...