242 citations · 1.3k across the 39 of their papers we have counts for
39 papers
Parker Bounds on Monopoles with Arbitrary Charge from Galactic and Primordial Magnetic Fields
Takeshi Kobayashi, Daniele Perri
We present a comprehensive study of Parker-type bounds on magnetic monopoles with arbitrary magnetic charge, including minicharged monopoles and magnetic black holes. We derive the…
Ultraviolet Sensitivity of Peccei-Quinn Inflation
Davide Dal Cin, Takeshi Kobayashi
The radial direction of the Peccei--Quinn field can drive cosmic inflation, given a non-minimal coupling to gravity. This scenario has been considered to simultaneously explain inf…
Parker Bound and Monopole Pair Production from Primordial Magnetic Fields
Takeshi Kobayashi, Daniele Perri
We present new bounds on the cosmic abundance of magnetic monopoles based on the survival of primordial magnetic fields during the reheating and radiation-dominated epochs. The new…
Monopole-Antimonopole Pair Production in Primordial Magnetic Fields
Takeshi Kobayashi
We show that monopoles can be pair produced by cosmological magnetic fields in the early universe. The pair production gives rise to relic monopoles, and at the same time induces a…
Impact of Helical Electromagnetic Fields on the Axion Window
Takeshi Kobayashi, Rajeev Kumar Jain
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…
Axionlike Origin of the Primordial Density Perturbation
Takeshi Kobayashi
We show that an axionlike field coupled to a new confining gauge group can generate the primordial density perturbation in the post-inflation universe. The axion decay constant and…