Related papers: Quintessence Axion Potential Induced by Electrowea…
Axions have emerged as compelling candidates for describing the dark sector of the Universe. In this work, we explore quintessence models inspired by axion-like potentials as a dynamical alternative to the cosmological constant. These…
The highly populated, low-energy excitations of a scalar field of mass $m_a\sim 10^{-22}\,\textrm{eV}$ can represent the full dark matter content of the universe and alleviate some tensions in the standard cosmological scenario on…
In this paper, dark energy is modelled via a spherically symmetric quintessence scalar field $\varphi$, the dynamics of which are found to be analogous to a pendulum. This is due to a driving axion potential $V(\left|\varphi\right|)$, whose…
Taking the recently reported non-zero rotation angle of the cosmic microwave background (CMB) linear polarization $\beta=0.35\pm0.14{\rm\, deg}$ as the hint for a pseudo Nambu-Goldstone boson quintessence dark energy (DE), we study the…
One of the simplest ways to account for the observed W-boson mass shift is to introduce the $SU(2)_L$ triplet Higgs boson with zero hypercharge, whose vacuum expectation value is about 3 GeV. If the triplet is heavy enough at…
We construct a model of the quintessence axion based on a gauged chiral $U(1)$ symmetry and an additional flat fifth dimension. The required high qualities are guaranteed by the brane separation. The observed cosmological constant (i.e.,…
If there is explicit violation of baryon plus lepton number at some energy scale, then the electroweak theory depends upon a {\theta}-angle. Due to a singular integration over small scale size instantons, this {\theta}-dependence is…
Using q-theory, we show that the electroweak crossover can generate a remnant vacuum energy density \Lambda \sim E_{ew}^8 / E_{planck}^4, with effective electroweak energy scale E_{ew} \sim 10^{3} GeV and reduced Planck-energy scale…
In this article the cosmological constant problems, as well as the astronomical evidence for a cosmologically significant homogeneous exotic energy density with negative pressure (quintessence), are reviewed for a broad audience of…
Adopting the q-theory approach to the cosmological constant problem, a simple field-theoretic model is presented which generates an effective cosmological constant (remnant vacuum energy density) of the observed order of magnitude,…
In axion quintessence, the cosmological era with an energy contrast in dark energy 0.1 < Omega_DE < 0.9 may represent a significant fraction of the universe's lifetime if the minimum of the axion potential is negative (unstable axion…
We present a theory with axion flux monodromies coupled to gravity, that reduces to the local vacuum energy sequester below the axion mass scales. If the axion potentials include a term generated by nonperturbative couplings to gauge…
I briefly review the cosmological constant problem and the issue of dark energy (or quintessence). Within the framework of quantum field theory, the vacuum expectation value of the energy momentum tensor formally diverges as $k^4$. A cutoff…
Inspired by the string axiverse idea, it has been suggested that the recent transition from decelerated to accelerated cosmic expansion is driven by an axion-like quintessence field with a sub-Planckian decay constant. The scenario requires…
It is suggested that the true ground state of the world has exactly vanishing vacuum energy and that the cosmological constant that seems to have been observed is due to our region of the universe being stuck in a false vacuum, whose energy…
A new component of the cosmic medium, a light scalar field or ''quintessence '', has been proposed recently to explain cosmic acceleration with a dynamical cosmological constant. Such a field is expected to be coupled explicitely to…
We show that axions interacting with abelian gauge fields obtain a potential from loops of magnetic monopoles. This is a consequence of the Witten effect: the axion field causes the monopoles to acquire an electric charge and alters their…
It is pointed out that a natural introduction of quintessence is an axion with an almost massless quark. With an appropriate gauge or discrete symmetry, one can obtain the quintessence potential height of order $(0.003 eV)^4$. Even though…
We point out that the swampland conjectures, forbidding the presence of global symmetries and (meta-)stable de Sitter vacua within quantum gravity, pick up a dynamical axion for the electroweak SU(2) gauge theory as a natural candidate for…
A slow-rolling scalar field ($Q\equiv$ Quintessence) with potential energy $V_Q\sim (3\times 10^{-3} {\rm eV})^4$ has been proposed as the origin of accelerating universe at present. We investigate the effective potential of $Q$ in the…