Related papers: Axionic Extensions of the Standard Model
Among solutions of the strong CP problem, the "invisible" axion in the narrow axion window is argued to be the remaining possibility among natural solutions on the smallness of $\bar{\theta}$. Related to the gravity spoil of global…
We overview our recent studies of cosmological models with expansion and global rotation. Problems of the early rotating models are discussed, and the class of new viable cosmologies is described in detail. Particular attention is paid to…
We perform a detailed dynamical analysis of various cosmological scenarios in extended (varying-mass) nonlinear massive gravity. Due to the enhanced freedom in choosing the involved free functions, this cosmological paradigm allows for a…
In supersymmetric extensions of the Standard Model, the lightest neutralino, the gravitino, and the axino can appear as the lightest supersymmetric particle and as such provide a compelling explanation of the non-baryonic dark matter in our…
String-inspired axion model is considered to comprehensively solve the problems of modern cosmology, Hubble tension problem, the origin of the stochastic gravitational wave background, and too early formation of supermassive black holes at…
We study axion cosmology in a 5D Universe, in the case of flat and warped extra dimension. The comparison between theoretical predictions and observations constrains the 5D axion decay constant and the 5D Planck mass, which has to be taken…
Many theoretically well-motivated extensions of the Standard Model of particle physics predict the existence of the axion and further ultralight axion-like particles. They may constitute the mysterious dark matter in the universe and solve…
The axion solution of the strong CP problem is reviewed together with the other strong CP solutions. We also point out the quintessential axion(quintaxion) whose potential can be extremely flat due to the tiny ratio of the hidden sector…
An extremely precise global symmetry is necessary in the Peccei--Quinn solution to the strong CP problem. Such symmetry arises when colored chiral fermions are localized in an internal space. We present a supersymmetric model that…
The fundamental action of superon-graviton model(SGM) for space-time and matter is written down explicitly in terms of the fields of the graviton and superons by using the affine and the spin connection formalisms, alternatively. Some…
A generic prediction of string theory is the existence of many axion fields. It has recently been argued that many of these fields should be light and, like the well known QCD axion, lead to observable cosmological consequences. In this…
We consider some questions of naturalness which arise when one considers conventional field theories in the presence of gravitation: the problem of global symmetries, the strong CP problem, and the cosmological constant problem. Using…
We study cosmological implications of supersymmetric axion models in which the axion scale is generated radiatively. Such models lead to the so-called thermal inflation and subsequent reheating should be constrained not to yield a too large…
This proceedings' contribution explores the rationale behind the axion as a resolution to the strong CP puzzle. It outlines various benchmark axion models and examines their implications, focusing on two key aspects: (i) the axion's…
Conventionally, the strong-$CP$ problem is assumed to be a naturalness puzzle, with the axion solution sometimes viewed as an ad hoc fix. Gravity is either ignored or taken as a threat for the global Peccei-Quinn symmetry. We explain that…
This work investigates alternative theories of gravity, the solutions to their field equations and the constraints that can be imposed upon them from observation and experiment. Specifically, we consider the cosmologies and spherically…
The axion, originally postulated by Peccei and Quinn to solve the strong CP problem, has become of great interest in particle and astroparticle phenomenology. Yet it has a problem. It is widely assumed that the axion leaves the…
A strictly linear evolution of the cosmological expansion scale factor is a characteristic feature in several classes of alternative gravity theories as also in the standard (big-bang) model with specially chosen equations of state of…
We present a construction of the superspace of maximally supersymmetric adS_{p+2} x S^{d-p-2} near-horizon geometry based entirely on the supergravity constraints of which the bosonic space is a solution. Besides the geometric superfields,…
We demonstrate that the observed cosmological excess of matter over antimatter may originate from a heavy QCD axion that solves the strong CP problem but has a mass much larger than that given by the Standard Model QCD strong dynamics. We…