Related papers: Wilsonian Dark Matter in String Derived $Z^\prime$…
Theories of dark matter that support bound states are an intriguing possibility for the identity of the missing mass of the Universe. This article proposes a class of models of supersymmetric composite dark matter where the interactions…
We consider models with extra U(1)' gauge symmetry that is broken spontaneously. In the models, there are cold dark matter candidates which are charged under U(1)' symmetry. Depending on the charge assignment, we can evade the strong bound…
After revisiting the heterotic string-derived low-energy effective model of \cite{Ashfaque:2016ydg, Athanasopoulos:2014bba, Faraggi:2016xnm, Ashfaque:2016jha} constructed in the four-dimensional free fermionic formulation, we find two…
Non-thermal cosmological histories are capable of greatly increasing the available parameter space of different particle physics dark matter (DM) models and are well-motivated by the ubiquity of late-decaying gravitationally coupled scalars…
The problem of dark energy arises due to its self-gravitating properties. Therefore explaining vacuum energy may become a question for the realm of quantum gravity, that can be addressed within string theory context. In this talk I…
In a recent paper, we identified a cosmological sector of a flipped $SU(5)$ model derived in the free fermionic formulation of the heterotic superstring, containing the inflaton and the goldstino superfields with a superpotential leading to…
Recent work has established a method of constructing non-supersymmetric string models that are stable, with near-vanishing one-loop dilaton tadpoles and cosmological constants. This opens up the tantalizing possibility of realizing stable…
We propose to search for a new type of gravitational wave signature relevant for particle physics models with symmetries broken at vastly different energy scales. The spectrum contains a characteristic double-peak structure consisting of a…
The discovery of the Higgs boson at the LHC supports the hypothesis that the Standard Model provides an effective parameterisation of all subatomic experimental data up to the Planck scale. String theory, which provides a viable…
Cosmologically long-lived, composite states arise as natural dark matter candidates in theories with a strongly interacting hidden sector at a scale of 10 - 100 TeV. Light axion-like states, with masses in the 1 MeV - 10 GeV range, are also…
Dark photon dark matter may be produced by the cosmic strings in association with the dark U(1) gauge symmetry breaking. We perform three-dimensional lattice simulations of the Abelian-Higgs model and follow the evolution of cosmic strings.…
We study the properties of classical vortex solutions in a non-Abelian gauge theory. A system of two adjoint Higgs fields breaks the SU(2) gauge symmetry to $Z_2$, producing 't Hooft-Polyakov monopoles trapped on cosmic strings, termed…
The Standard Model indicates the realization of grand unified structures in nature, and can only be viewed as an effective theory below a higher energy cutoff. While the renormalizable Standard Model forbids proton decay mediating operators…
Cold dark matter axions produced in the post-inflationary Peccei-Quinn symmetry breaking scenario serve as clear targets for their experimental detection, since it is in principle possible to give a sharp prediction for their mass once we…
We systematically study the possibilities for asymmetric dark matter in the context of non-supersymmetric SO(10) models of grand unification. Dark matter stability in SO(10) is guaranteed by a remnant $\mathbb{Z}_2$ symmetry which is…
Potentially realistic string models often contain additional abelian gauge factors besides the standard model group. The consequences of such extended gauge structure are manifold both for theory and phenomenology as I show focussing in the…
The existence of the neutrino mass and flavor mixing have been experimentally verified. These phenomena strongly motivate to extend the Standard Model (SM). Amongst many possibilities, a simple and interesting extension of the SM can be…
In gauge systems coupled to matter, the static potential flattens out at a scale where the confining string breaks by formation of a dynamical pair of particles. Surprisingly, such a breaking is invisible in Wilson loops even when the…
Axions have long been considered plausible candidates for dark matter. The axion dark matter emitted from cosmic strings after the Peccei-Quinn (PQ) symmetry breaking in the early Universe was extensively simulated. In this work, we study…
We propose a new scenario for generating a relic density of non-relativistic dark matter in the context of heterotic string theory. Contrary to standard thermal freeze-out scenarios, dark-matter particles are abundantly produced while still…