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Solitons and black hole in shift symmetric scalar-tensor gravity with cosmological constant
(Springer, 2018-06-14)
We demonstrate the existence of static, spherically symmetric globally regular, i.e. solitonic solutions of a shift-symmetric scalar-tensor gravity model with negative cosmological constant. The norm of the Noether current ...
Fitting BICEP2 with defects, primordial gravitational waves and dust
(IOP Publishing, 2015)
In this work we discuss the possibility of cosmic defects being responsible for the B-mode signal measured by the BICEP2 collaboration. We also allow for the presence of other cosmological sources of B-modes such as ...
Scaling density of axion strings
(APS, 2020-01-16)
In the QCD axion dark matter scenario with postinflationary Peccei-Quinn symmetry breaking, the number density of axions, and hence the dark matter density, depends on the length of string per unit volume at cosmic time ...
Approach to scaling in axion string networks
(APS, 2021-05-26)
We study the approach to scaling in axion string networks in the radiation era, through measuring the root-mean-square velocity v as well as the scaled mean string separation x. We find good evidence for a fixed point in ...
Irreducible background of gravitational waves from a cosmic defect network: update and comparison of numerical techniques
(APS, 2020-11-13)
Cosmological phase transitions in the early Universe may produce relics in the form of a network of cosmic defects. Independently of the order of a phase transition, topology of the defects, and their global or gauge nature, ...
Type I Abelian Higgs strings: evolution and Cosmic Microwave Background constraints
(APS, 2019-04-26)
We present results from the first simulations of networks of Type I Abelian Higgs cosmic strings to include both matter and radiation eras and cosmic microwave background (CMB) constraints. In Type I strings, the string ...
The strong backreaction regime in axion inflation
(APS, 2023-10-13)
We study the nonlinear dynamics of axion inflation, capturing for the first time the inhomogeneity and full dynamical range during strong backreaction, till the end of inflation. Accounting for inhomogeneous effects leads ...
Loop decay in Abelian-Higgs string networks
(APS. American Physical Society, 2021-08-16)
We study the decay of cosmic string loops in the Abelian-Higgs model. We confirm earlier results that loops formed by intersections of infinite strings formed from random-field initial conditions disappear quickly, with ...
Nambu-Goto Dynamics of Field Theory Cosmic String Loops
(IOP Publishing, 2023-05-18)
We perform a detailed comparison of the dynamics of cosmic string loops obtained in cosmological field theory simulations with their expected motion according to the Nambu-Goto action. We demonstrate that these loops follow ...