scholarly journals Cosmic Strings as a Candidate for Dark Matter. Astrophysical Formulae

1988 ◽  
Vol 130 ◽  
pp. 566-566
Author(s):  
M.P. Dabrowski ◽  
J. Stelmach
Keyword(s):  
Dark Matter ◽  
Domain Walls ◽  
Analytic Solution ◽  
Cosmic Strings ◽  
Isotropic Universe ◽  
Stable Domain ◽  
Homogeneous Isotropic Universe ◽  
Weierstrass Functions ◽  
Arbitrary Curvature

We consider homogeneous, isotropic universe with arbitrary curvature (k=0, ±1), filled with dust, radiation, ˄-term and a set of noninteracting strings (i.e. scaling as ρs ∼ R−2, hence yielding string dominated universe). For such model we find analytic solution of the Friedman equation using Weierstrass functions. We realize that addition of (rather unrealistic component) stable domain walls (ρw ∼ R−1) to the model, does not essentially complicate the calculations.

scholarly journals Comments on axions, domain walls, and cosmic strings

2021 ◽  
Vol 2021 (11) ◽  
pp. 041
Author(s):  
Michael Dine ◽  
Nicolas Fernandez ◽  
Akshay Ghalsasi ◽  
Hiren H. Patel
Keyword(s):  
Dark Matter ◽  
Domain Walls ◽  
Cosmic Strings ◽  
Collective Modes ◽  
Plausible Candidate ◽  
The Subject

Abstract Axions have for some time been considered a plausible candidate for dark matter. They can be produced through misalignment, but it has been argued that when inflation occurs before a Peccei-Quinn transition, appreciable production can result from cosmic strings. This has been the subject of extensive simulations. But there are reasons to be skeptical about the possible role of axion strings. We review and elaborate on these questions, and argue that parametrically strings are already accounted for by the assumption of random misalignment angles. We review and elaborate on these questions, and provide several qualitative arguments that parametrically strings are already accounted for by the assumption of random misalignment angles. The arguments are base on considerations of the collective modes of the string solutions, on computations of axion radiation in particular models, and reviews of simulations.

scholarly journals Domain walls in 4d $$ \mathcal{N} $$ = 1 SYM

2021 ◽  
Vol 2021 (3) ◽  
Author(s):  
Diego Delmastro ◽  
Jaume Gomis
Keyword(s):  
Domain Wall ◽  
Domain Walls ◽  
Simons Theory ◽  
Partition Functions ◽  
Quantum Field Theories ◽  
Yang Mills ◽  
Stable Domain ◽  
Coxeter Number ◽  
Topological Quantum ◽  
Simply Connected

Abstract 4d$$ \mathcal{N} $$ N = 1 super Yang-Mills (SYM) with simply connected gauge group G has h gapped vacua arising from the spontaneously broken discrete R-symmetry, where h is the dual Coxeter number of G. Therefore, the theory admits stable domain walls interpolating between any two vacua, but it is a nonperturbative problem to determine the low energy theory on the domain wall. We put forward an explicit answer to this question for all the domain walls for G = SU(N), Sp(N), Spin(N) and G2, and for the minimal domain wall connecting neighboring vacua for arbitrary G. We propose that the domain wall theories support specific nontrivial topological quantum field theories (TQFTs), which include the Chern-Simons theory proposed long ago by Acharya-Vafa for SU(N). We provide nontrivial evidence for our proposals by exactly matching renormalization group invariant partition functions twisted by global symmetries of SYM computed in the ultraviolet with those computed in our proposed infrared TQFTs. A crucial element in this matching is constructing the Hilbert space of spin TQFTs, that is, theories that depend on the spin structure of spacetime and admit fermionic states — a subject we delve into in some detail.

Late universe expansion dominated by domain walls and dissipative dark matter

2004 ◽  
Vol 70 (4) ◽  
Author(s):  
Sergio del Campo ◽  
Ramón Herrera ◽  
Diego Pavón
Keyword(s):  
Dark Matter ◽  
Domain Walls ◽  
Universe Expansion

Vortons: Dark Matter From Cosmic Strings

1999 ◽  
pp. 325-326
Author(s):  
C. J. A. P. Martins ◽  
E. P. S. Shellard
Keyword(s):  
Dark Matter ◽  
Cosmic Strings

scholarly journals QCD axion dark matter from long-lived domain walls during matter domination

2018 ◽  
Vol 782 ◽  
pp. 1-5 ◽  
Author(s):  
Keisuke Harigaya ◽  
Masahiro Kawasaki
Keyword(s):  
Dark Matter ◽  
Domain Walls

Cosmic strings and domain walls

1985 ◽  
Vol 121 (5) ◽  
pp. 263-315 ◽  
Author(s):  
Alexander Vilenkin
Keyword(s):  
Domain Walls ◽  
Cosmic Strings

scholarly journals Galaxy Formation with Hot Dark Matter and Cosmic Strings

1988 ◽  
Vol 130 ◽  
pp. 560-561
Author(s):  
Robert H. Brandenberger
Keyword(s):  
Dark Matter ◽  
Galaxy Formation ◽  
Cosmic Strings ◽  
Severe Problem ◽  
Small Scales ◽  
The Galaxy

Hot dark matter particles have large thermal velocities at teg and hence cannot be gravitationally bound on small scales (free streaming). In models of formation of structure based on linear adiabatic perturbations all inhomogeneities on scales smaller than the maximal free streaming length λj are washed out. The mass λj inside a bail of radius exceeds the galaxy mass. Hence in the above models galaxies can only lorm by fragmentation of larger-scale objects. This is a severe problem.

Sign in / Sign up

Export Citation Format

Share Document