Related papers: Comment on "More Axions from Strings''
We obtain the equations of motion for cosmic strings in extensions of the 3+1 FRW model with extra dimensions. From these we derive a generalisation of the Velocity-dependent One-Scale (VOS) model for cosmic string network evolution which…
Many theoretically well-motivated extensions of the Standard Model contain heavy pseudoscalars that couple to hypercharge topological density. The cosmological dynamics of such hypercharge axions could, under certain conditions, lead to…
We study the evolution of domain wall networks appearing after phase transitions in the early Universe. They exhibit interesting dynamical scaling behaviour which is not yet well understood, and are also simple models for the more…
We make use of the formalism described in a previous paper [Martins {\it et al.} Phys. Rev. D90 (2014) 043518] to address general features of wiggly cosmic string evolution. In particular, we highlight the important role played by poorly…
We study the minimal requirements to obtain axion strings for axions with exponentially good quality. These ingredients appear in theories where an axion coming from a higher-form gauge field mixes with the phase of a complex scalar field…
If the QCD axion solves the strong CP problem then light axion-like-particles (ALPs) are expected to be ubiquitous in string theory - the string axiverse. Such ALPs can be the QCD axion and constitute dark matter (DM) or radiation,…
If the axion exists and if the initial axion field value is uncorrelated at causally disconnected points, then it should be possible to predict the efficiency of cosmological axion production, relating the axionic dark matter density to the…
We propose heavy axions as a natural superheavy dark matter candidate in string theory, with the relic density of dark matter originating in quantum fluctuations during cosmic inflation. String Theory is well known for the possibility of…
We propose the mechanism to disentangle the decay constant of closed string axion from the string scale in the framework of type II string theory on Calabi-Yau manifold. We find that the quantum and geometrical corrections in the…
We present a string-based picture of the cosmological evolution in which (CP-violating) gravitational anomalies acting during the inflationary phase of the universe cause the vacuum energy density to "run" with the effective Hubble…
Lack of knowledge about the background expansion history of the Universe from independent observations makes it problematic to obtain a precise and accurate estimation of the Hubble constant $H_0$ from gravitational wave standard sirens,…
String theory has been claimed to give rise to natural fuzzy dark matter candidates in the form of ultralight axions. In this paper we revisit this claim by a detailed study of how moduli stabilisation affects the masses and decay constants…
Measurements of the Hubble constant, and more generally measurements of the expansion rate and distances over the interval $0 < z < 1$, appear to be inconsistent with the predictions of the standard cosmological model ($\Lambda$CDM) given…
String theory/M-theory generally predicts that axionic fields with a broad mass spectrum extending below 10^{-10}eV are produced after compactification to four dimensions. These axions/fields provoke a rich variety of cosmophysical…
We extend our earlier model of the small scale structure of cosmic string networks through an improved treatment of the separation of long and short scales. We find that the production of small loops (at the gravitational radiation scale)…
Global cosmic strings are generically predicted in particle physics beyond the Standard Model, e.g., a post-inflationary global $U(1)$ symmetry breaking which may associate with axion-like dark matter. We demonstrate that although…
The Standard Cosmological Model has experienced tremendous success at reproducing observational data by assuming a universe dominated by a cosmological constant and dark matter in a flat geometry. However, several studies, based on local…
Axions arising as modes of higher-dimensional gauge fields are known to offer a compelling solution to the axion quality problem and to naturally arise in string theory. In this context, it is interesting to ask how we would interpret an…
Cosmic strings, topological defects predicted by high-energy theories, may contribute to the late-time expansion of the Universe, effectively mimicking dynamical dark energy. We investigate four phenomenological extensions of the…
Classical lattice simulations of the Abelian Higgs model are used to investigate small scale structure and loop distributions in cosmic string networks. Use of the field theory ensures that the small-scale physics is captured correctly. The…