We consider a feeble long range scalar force that mainly couples to dark matter and unstable Standard Model states, like the $\mu$. The induced background scalar field depends on dark matter number density, causing the mass of the unstable particles to have spatial and temporal variations. These variations would leave an imprint on the value of the fine structure constant $\alpha$. This...
Future measurements of primordial non-Gaussianity (NG) can reveal cosmologically produced particles with masses of order the inflationary Hubble scale, which can be as high as $\sim 10^{14}$ GeV. I will describe how (partially) Higgsed gauge theories, naturally having particles with Hubble scale masses, can leave observable signatures in future NG measurements giving us a chance to do...
The Standard Model Higgs boson, which has previously been shown to develop an effective vacuum expectation value during inflation, can give rise to large particle masses during inflation and reheating, leading to temporary blocking of the reheating process and a lower reheat temperature after inflation. We study the effects on the multiple stages of reheating: resonant particle production...
In this talk I will present some original work in which we suggest that the relic density of dark matter may be produced thermally in a hidden sector whose interaction with the standard model is exclusively passing through the inflationary sector. I will show that the parameter space required for such an inflaton portal is extremely natural as compared to previous proposals on highly decoupled...
Recently the Experiment to Detect the Global Epoch of Reionization Signature (EDGES) reported the detection of a 21cm absorption signal stronger than astrophysical expectations. The radiation from dark matter (DM) decay and primordial black holes (PBH) injects energy into the intergalactic medium, which can heat up neutral hydrogen gas and weaken the 21cm absorption signal imposing...
Future neutron-antineutron ($n$-$\bar n$) oscillation experiments, such as at the European Spallation Source (ESS), aim to find first evidence of baryon number violation. We investigate implications of an improved $n$-$\bar n$ oscillation search for baryogenesis via interactions of $n$-$\bar n$ mediators, parameterized by an effective field theory (EFT). We find first and foremost that even in...
Sub-MeV dark matter remains unconstrained by direct detection, and there are several well-motivated candidates in this mass range. Electron recoil experiments have been proposed as a technique to detect such a light particle, but little is known about the extent of cosmological restrictions on a generic light species coupled to electrons. We study cosmological constraints on a light dark...
We have studied the statistical properties and the associated realizability condition for helical primordial magnetic fields. These have been related to the smoothed magnetic fields generally used to constrain the fields from observational data. In particular, we have looked at fields generated during inflation which have a scale-invariant spectrum. We have determined the relation between the...