5 papers
Constraining axion quadratic couplings with the Hulse-Taylor binary system
Ziwen Yin, Shyam Balaji, Malcolm Fairbairn +1
The orbital evolution of the Hulse-Taylor binary neutron star system is described to high precision by general relativity, in which gravity is the only long-range force and gravita…
Primordial Black Hole Abundance from Reionization
Ziwen Yin, Hanyu Cheng, Luca Visinelli
We derive robust constraints on the initial abundance of evaporating primordial black holes (PBHs) using the reionization history of the Universe as a cosmological probe. We focus…
Constraining the axiverse with reionization
Ziwen Yin, Hanyu Cheng, Eleonora Di Valentino +3
Axions that couple to electromagnetism are produced in the early Universe by, among other channels, freeze-in via the Primakoff process. For sufficiently large axion masses, the sa…
Constraining exotic high- reionization histories with Gaussian processes and the Cosmic Microwave Background
Hanyu Cheng, Ziwen Yin, Eleonora Di Valentino +2
The large-angle polarization anisotropies in the Cosmic Microwave Background (CMB) arise from Thomson scattering of CMB photons off free electrons in the post-recombination Univers…
Axion star condensation around primordial black holes and microlensing limits
Ziwen Yin, Luca Visinelli
We present novel findings concerning the parameter space of axion stars, extended object forming in dense dark matter environments through gravitational condensation. We emphasize…