Related papers: A cosmological bound on $e^+ e^-$ mass difference
We consider a massive scalar field with a coordinate-dependent mass in higher-dimensional spacetime. The field satisfies Dirichlet boundary conditions on a brane representing the four-dimensional world. Despite being massive, the theory is…
Our knowledge of the mass composition of cosmic rays is deficient at all energies above 10^17. Here systematic differences between different measurements are discussed and, in particular, it is argued that there is no compelling evidence to…
We derive stronger bounds on the magnetic monopole charge of the proton, and hence on non-associative quantum mechanics from measurements of the magnetic fields of the Earth, the Moon and Mars. Limits are several orders of magnitude…
In this paper it is given a brief review of the current limits on the magnitude of CPT and Lorentz Invariance violations, currently predicted in connection with quantum gravity and string/M-theory, that can be derived from astrophysical and…
An investigation is performed of the Lorentz-violating electrodynamics extracted from the renormalizable sector of the general Lorentz- and CPT-violating standard-model extension. Among the unconventional properties of radiation arising…
Although there is overwhelming evidence of dark matter from its gravitational interaction, we still do not know its precise gravitational interaction strength or whether it obeys the equivalence principle. Using the latest available…
Photons traveling cosmological distances through the inhomogeneous Universe experience a great variation in their in-medium induced effective mass. Using the EAGLE suite of hydrodynamical simulations, we infer the free electron distribution…
We consider a universe with a compact extra dimension and a cosmological constant emerging from a suitable ultraviolet cutoff on the zero point energy of the vacuum. We derive the Casimir force between parallel conducting plates as a…
In the context of Standard Model Extensions (SMEs), we analyse four general classes of Super Symmetry (SuSy) and Lorentz Symmetry (LoSy) breaking, leading to {observable} imprints at our energy scales. The photon dispersion relations show a…
The possible cosmological variation of the proton-to-electron mass ratio was estimated by measuring the H_2 wavelengths in the high-resolution spectrum of the quasar Q~0347-382. Our analysis yielded an estimate for the possible deviation of…
The observed accelerated cosmic expansion is problematic in that it seems to require an otherwise unobserved dark energy for its origin. A possible alternative explanation has been recently given, which attempts to account for this…
The photon is the paradigm for a massless particle and current experimental tests set severe upper bounds on its mass. Probing such a small mass, or equivalently large Compton wavelength, is challenging at laboratory scales, but planetary…
In theories with large extra dimensions, constraints from cosmology lead to non-trivial lower bounds on the fundamental scale M_F, corresponding to upper bounds on the radii of the compact extra dimensions. These constraints are especially…
Using considerations from the Quantum Zero Point Field and Thermodynamics, we show that the Planck Scale is the minimum (maximum mass) and the Photon Scale is the maximum (minimum mass) Scale in the universe. The arguments also deduce the…
The source of CPT-violation in the photon sector of the Standard Model Extension arises from a Chern-Simons-like contribution that involves a coupling to a fixed background vector field $k_{AF}^\mu$. These Lorentz- and CPT-violating photons…
The discovery that the expansion of the universe is accelerating in time is a major discovery which still awaits adequate explanation. It is generally agreed that this implies a cosmic repulsion as a result of the existence of a…
Cosmological implications of asymmetry between particles and antiparticles are reviewed. Three possible mechanisms of CP-violation in cosmology are described. General features of kinetics of generation of cosmological charge asymmetry are…
The data collected by ATIC, PPB-BETS, FERMI-LAT and HESS all indicate that there is an electron/positron excess in the cosmic ray energy spectrum above $\sim$ 100 GeV, although different instrumental teams do not agree on the detailed…
A hypothetical photon mass, $m_{\gamma}$, can produce a frequency-dependent vacuum dispersion of light, which leads to an additional time delay between photons with different frequencies when they propagate through a fixed distance. The…
Dark photons, a generic class of light gauge bosons that interact with the Standard Model (SM) exclusively through kinetic mixing, arise naturally in many gauge extensions of the SM. Motivated by these theoretical considerations, we present…