97 citations · 309 across the 12 of their papers we have counts for
12 papers
Extended FLRW Models: dynamical cancellation of cosmological anisotropies
Mikjel Thorsrud, Ben D. Normann, Thiago S. Pereira
We investigate a corner of the Bianchi models that has not received much attention: "extended FLRW models" (eFLRW) defined as a cosmological model with underlying anisotropic Bianc…
A study of inhomogeneous massless scalar gauge fields in cosmology
Ben David Normann, Sigbjørn Hervik, Angelo Ricciardone +1
Why is the Universe so homogeneous and isotropic? We summarize a general study of a -law perfect fluid alongside an inhomogeneous, massless scalar gauge field (with homogeneous…
Bianchi models with a free massless scalar field: invariant sets and higher symmetries
Mikjel Thorsrud
We scrutinize the overall structure of the space of cosmological models of Bianchi type I-VII that contain a free massless scalar field, with a spatially homogeneous gradient $…
Bianchi cosmologies with -form gauge fields
Ben David Normann, Sigbjørn Hervik, Angelo Ricciardone +1
In this paper the dynamics of free gauge fields in Bianchi type I-VII space-times is investigated. The general equations for a matter sector consisting of a -form field st…
Balancing Anisotropic Curvature with Gauge Fields in a Class of Shear-Free Cosmological Models
Mikjel Thorsrud
We present a complete list of general relativistic shear-free solutions in a class of anisotropic, spatially homogeneous and orthogonal cosmological models containing a collection…
General quadrupolar statistical anisotropy: Planck limits
S. Ramazanov, G. Rubtsov, M. Thorsrud +1
Several early Universe scenarios predict a direction-dependent spectrum of primordial curvature perturbations. This translates into the violation of the statistical isotropy of cos…
Statistics of Anisotropies in Inflation with Spectator Vector Fields
Mikjel Thorsrud, Federico R. Urban, David F. Mota
We study the statistics of the primordial power spectrum in models where massless gauge vectors are coupled to the inflaton, paying special attention to observational implications…
Local Observables in a Landscape of Infrared Gauge Modes
Mikjel Thorsrud, David F. Mota, Federico R. Urban
Cosmological local observables are at best statistically determined by the fundamental theory describing inflation. When the scalar inflaton is coupled uniformly to a collection of…
Quintessence with Kaluza-Klein type couplings to matter and an isotropy-violating vector field
Mikjel Thorsrud
We study the dynamics of a scalar field with Kaluza-Klein type couplings to cold dark matter and an isotropy-violating vector field. The vector coupling, , has been stud…
Cosmologies in Horndeski's second-order vector-tensor theory
John D. Barrow, Mikjel Thorsrud, Kei Yamamoto
Horndeski derived a most general vector-tensor theory in which the vector field respects the gauge symmetry and the resulting dynamical equations are of second order. The action co…
Cosmology of a Scalar Field Coupled to Matter and an Isotropy-Violating Maxwell Field
Mikjel Thorsrud, David F. Mota, Sigbjørn Hervik
Motivated by the couplings of the dilaton in four-dimensional effective actions, we investigate the cosmological consequences of a scalar field coupled both to matter and a Maxwell…
Inflation with stable anisotropic hair: is it cosmologically viable?
Sigbjørn Hervik, David F. Mota, Mikjel Thorsrud
Recently an inflationary model with a vector field coupled to the inflaton was proposed and the phenomenology studied for the Bianchi type I spacetime. It was found that the model…