Related papers: A $p$-Adic Matter in a Closed Universe
String theories suggest the existence of a plethora of axion-like fields with masses spread over a huge number of decades. Here we show that these ideas lend themselves to a model of quintessence with no super-Planckian field excursions and…
We show results for the expected reach of the network of experiments that is being set up globally with the aim of detecting the "invisible" axion, in light of a non-standard thermal history of the universe. Assuming that the axion is the…
We study new physical phenomena and constraints in generalized scalar--tensor theories of gravity with $\Phi$--dependent masses. We investigate a scenario (which can arise in string theories) with two types of $\Phi$--dependent masses which…
The axion is an intriguing dark matter candidate emerging from the Peccei-Quinn solution to the strong CP problem. Current experimental searches for axion dark matter focus on the axion mass range below 40 $\mu$eV. However, if the…
Dark matter effects may be attributed to interactions between the Machian strings connecting every pair of elementary particles in the observable Universe. A simple model for the interaction between Machian strings is proposed. In the early…
The axion is a light pseudoscalar particle postulated to solve issues with the Standard Model, including the strong CP problem and the origin of dark matter. In recent years, there has been remarkable progress in the physics of axions in…
A new realization of the matter Lagrangian is introduced which models the dark energy component as a non-standard combination of thermodynamics quantities of the baryonic matter. We will prove that the present realization is independent of…
The axion or axion-like particle motivated from a natural solution of strong CP problem or string theory is a promising dark matter candidate. We study the new observational effects of ultralight axion-like particles by the space-borne…
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…
We construct a theory in which the solution to the strong CP problem is an emergent property of the background of the dark matter in the Universe. The role of the axion degree of freedom is played by multi-body collective excitations…
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,…
The paper aims to consider the electromagnetic adjoint-field in the complex octonion space as the dark matter field, describing some properties of dark matter, especially the origin, particle category, existence region, and force and so…
From astronomical observations, we know that dark matter exists, makes up 23% of the mass budget of the Universe, clusters strongly to form the load-bearing frame of structure for galaxy formation, and hardly interacts with ordinary matter…
We present a new set of analytic solutions of general relativity with a negative cosmological constant, which describe black strings and black p-branes in arbitrary number of dimensions, $D$. The solutions are supported by minimally…
The nature of the cosmological dark matter remains elusive. Recent studies have advocated the possibility that dark matter could be composed of ultra-light, self-interacting bosons, forming a Bose-Einstein condensate in the very early…
The origin of dark matter in the universe may be weakly interacting scalar particles produced by amplification of quantum fluctuations during a period of dilaton-driven inflation. We present two interesting cases, the case of small…
Dark matter constitutes about $23\%$ of the total energy density of the universe but its properties are still little known besides that it should be composed by cold and weakly interacting particles. Many beyond standard model theories can…
In this paper, we offer a brief introduction to the $p$-adic numbers and operations in the metric space defined under the $p$-adic norm. Specifically, we provide a clear description of the derivation of the $p$-adic number via the…
There is plenty of evidence that most matter in the Universe is dark (non-luminous). Particle physics offers several possible explanations. In this talk I focus on cold dark matter; the most promising candidates are then axions and the…
We study the world-volume effective action of Dp-brane at the tachyonic vacuum which is equivalent to the zero tension limit. Using the Hamiltonian formalism we discuss the algebra of constraints and show that there is a non-trivial ideal…