Search arXiv⌕ Search
Home/Archive/arXiv

arXiv · hep-ph/9806202

Dark Matter Axions in Models of String Cosmology

Ram Brustein·Merav Hadad
View original source ↗Read source document ↗Export metadata ↓

Abstract

Axions are produced during a period of dilaton-driven inflation by amplification of quantum fluctuations. We show that for some range of string cosmology parameters and some range of axion masses, primordial axions may constitute a large fraction of the present energy density in the universe in the form of cold dark matter. Due to the periodic nature of the axion potential energy density fluctuations are strongly suppressed. The spectrum of primordial axions is not thermal, allowing a small fraction of the axions to remain relativistic until quite late.

Explore related subjects

hep-phastro-phhep-th

Keep this discovery

Explore connections, maps & timelines

BibTeXRIS

Ram Brustein, Merav Hadad. 1998-05-30. Dark Matter Axions in Models of String Cosmology. https://doi.org/10.1016/s0370-2693(98)01206-4

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related papers

arXiv2026

Violation of Parity and Flavor Symmetries in a Nambu-Jona-Lasinio Model

We study a lattice Nambu-Jona-Lasinio model with certain continuous chiral and two-flavor symmetries. For the Hamiltonian of the model, we construct a ground state which breaks the parity and flavor symmetries. In our argument, the chiral symmetry plays a crucial role for proving the violation of the parity and flavor symmetries, although the model does not contain the so-called Wilson term.

hep-ph↗
arXiv2026

Generic framework for non-perturbative QCD in light hadrons

In this paper, we review several topological aspects of the QCD vacuum and recent progress on this quantitative framework for the low-lying hadron physics rooted in QCD by introducing the vacuum as a liquid of pseudoparticles. We have developed systematic density expansion on the dilute vacuum to calculate the vacuum expectation values (VEVs) and generalize the calculations to hadronic matrix element and hadronic form factors using the instanton liquid model (ILM). Thereby, the nonperturbative physics can be analyzed in a systematic framework with a few parameters: instanton size $ρ$ and instanton density $n_{I+A}$, and current quark mass $m$.

hep-ph↗
arXiv2026

Slow Quanta Bound States and a Possible Link to Dark Matter

We study the possibility of elementary energy quanta with vacuum propagation speed w < c, capable of interacting with each other to form massive bound states. The slow matter thus formed is shown to follow laws of Special Relativity mediated by velocity w rather than c, and to possess dynamical properties recalling some characteristics of Dark Matter.

hep-ph↗