4 papers
ACT stands for Awkward Cosmology Theories
Loris Del Grosso, Alfredo Urbano, Marcello Ziccolella
Recent observations from the Atacama Cosmology Telescope (ACT) point to a scalar spectral index in tension with the predictions of Starobinsky inflation. Two main strategies have b…
Primordial Black-Hole-Based Pathways to Little Red Dots
Valerio De Luca, Loris Del Grosso, Gabriele Franciolini +4
The James Webb Space Telescope has uncovered a population of compact, high-redshift sources, the Little Red Dots (LRDs), which may host supermassive black holes (BHs) significantly…
Off-Equatorial Orbits around Magnetically Charged Black Holes
Xilai Li, Loris Del Grosso, David E. Kaplan
We present a complete characterization of stable, off-equatorial circular orbits around magnetically charged black holes (MBHs). For a static, spherically symmetric MBH, we derive…
Cosmological Consequences of Unconstrained Gravity and Electromagnetism
Loris Del Grosso, David E Kaplan, Tom Melia +3
Motivated by the quantum description of gauge theories, we study the cosmological effects of relaxing the Hamiltonian and momentum constraints in general relativity and Gauss' law…