Related papers: Constraints on background torsion field from K phy…
We consider cosmological constraints arising from the background expansion history on the ef- fective field theory of cosmic acceleration, a theoretical framework that allows for a unified way to classify both models of dark energy and…
We suggest a new experiment sensitive to a possible difference between the amount of CP violation as measured on the surface of the Earth and in a lower gravity environment. Our proposed experiment is model independent and could yield a…
In this paper we study the possibility of testing Charge-Parity-Time Reversal (CPT) symmetry with cosmic microwave background (CMB) experiments. We consider two kinds of Chern-Simons (CS) term, electromagnetic CS term and gravitational CS…
We show that the CP-violating effect in K^0 vs \bar K^0-->\pi^+\pi^-\pi^0 decays differs from that in K_{\rm L}-->\pi^+\pi^-, K_{\rm L}-->\pi^0\pi^0 or the semileptonic K_{\rm L} transitions, if there exists CPT violation in K^0-\bar{K}^0…
We report on the search for Lorentz violating sidereal variations of the frequency difference of co-located spin-species while the Earth and hence the laboratory reference frame rotates with respect to a relic background field. The…
Effective Field Theory techniques are used to study the leading order quantum corrections to the gravitational wave backreaction. The effective stress-energy tensor is calculated and it is shown that it has a non-vanishing trace that…
In gravitation theory with a background metric, a gravitational field is described by a (1,1)-tensor field. The energy-momentum conservation law imposes a gauge condition on this field.
Analytical solutions with effective CPT-violating spin--gravity corrections to the neutron's gravitational bound states are obtained. The helicity-dependent phase evolution due to $\vec{\sigma}\cdot\vec{\tilde{b}}$ and…
We discuss the possibility of observing CPT violation from top anti-top production in hadronic colliders. We study a general approach by analyzing constraints on the mass difference between the top and anti-top quarks. We present current…
K-essence is a possible candidate for dark energy of the Universe. In this paper we consider couplings of k-essence to the matter fields of the standard electroweak theory and study the effects of the cosmological CPT violation induced by…
Transverse polarization (TP) can be used to study interference of (S,P) or T type couplings from new physics with the SM contribution. In e+e- -> t tbar, a CP-odd azimuthal asymmetry can constrain the scale Lambda of new (S,P) or T contact…
We study the effect of background geometry generated by a thin cosmic string on the anomalous magnetic moment of the electron. We find that the magnitude of the quantum correction to the magnetic moment depends on the distance from the…
Minimal CPT violation has been constrained using observations of neutral-meson oscillations. Violation of CPT symmetry arising from nonminimal operators in the Lagrange density can also occur. A general approach using scalar effective field…
The one-loop divergences for the scalar field theory with Lorentz and/or CPT breaking terms are obtained in curved space-time. We analyze two separate cases: minimal coupled scalar field with gravity and nonminimal one. For the minimal case…
A teleparallel G\"{o}del universe is shown to lead to a simple and natural relation between Cartan torsion and the global rotation of the universe.This is straightforward if one uses the formalism of Cartan's calculus of exterior…
The strongest bounds on some forms of Lorentz and CPT violation come from astrophysical data, and placing such bounds may require understanding and modeling distant sources of radiation. However, it is also desirable to have bounds that do…
We calculate the power spectrum of the stochastic gravitational wave (GW) background expected from kink-kink collisions on infinite cosmic strings. Intersections in the cosmic string network continuously generate kinks, which emit GW bursts…
Cosmological CPT violation will rotate the polarized direction of CMB photons, convert partial CMB E mode into B mode and vice versa. It will generate non-zero EB, TB spectra and change the EE, BB, TE spectra. This phenomenon gives us a way…
It is shown that there exists, in the field theory of gravitation, contrary to the General Theory of Relativity (GTR), a bound for admissible time slowing down by the gravitational field which excludes a possibility of unbounded compression…
A non-vanishing vacuum expectation value for an antisymmetric tensor field leads to the violation of Lorentz invariance on the brane. This violation is controlled by the $\theta_{\mu \nu}$ parameter, which has a dimension of inverse mass…