相关论文: Scale hierarchy in Horava-Lifshitz gravity: a stro…

Special relativity asserts that physical phenomena appear the same for all inertially moving observers. This symmetry, called Lorentz symmetry, relates long wavelengths to short ones: if the symmetry is exact it implies that spacetime must…

We set constraints on O(E/M) Lorentz Violation in QED in an effective field theory framework. A major consequence of such assumptions is the modification of the dispersion relations for electrons/positrons and photons, which in turn can…

It has been argued by Jacobson, Liberati and Mattingly that synchrotron radiation from the Crab Nebula imposes a stringent constraint on any modification of the dispersion relations of the electron that might be induced by quantum gravity.…

We show that coupling the Standard Model to a Lorentz symmetry violating sector may co-exist with viable phenomenology, provided that the interaction between the two is mediated by higher-dimensional operators. In particular, if the new…

In this work, we consider the Ho\v{r}ava-Lifshitz scaling to rewrite higher-order derivatives in Lorentz-violating CPT-even electrodynamics. The possibility of the Lorentz invariance violation being originally suppressed by the quantum…

Recently two collaborations, Tibet and HAWC, presented new measurements of gamma-ray spectrum from Crab Nebula \cite{Amenomori:2019rjd},\cite{Abeysekara:2019edl} which continues beyond $100$ TeV. We use these data to establish two-sided…

We consider the role of matter in the non-projectable version of Horava-Liftshitz gravity at both a classical and a quantum level. At the classical level, we construct general forms of matter Lagrangians consistent with the reduced symmetry…

We argue that the true nature of the renormalizability of Horava-Lifshitz gravity lies in the presence of higher order spatial derivatives and not in the anisotropic Lifshitz scaling of space and time. We discuss the possibility of…

We use observational data from Type Ia Supernovae (SNIa), Baryon Acoustic Oscillations (BAO), and Cosmic Microwave Background (CMB), along with requirements of Big Bang Nucleosynthesis (BBN), to constrain the cosmological scenarios governed…

Constraints on possible Lorentz symmetry violation (LV) of order E/M_Planck for electrons and photons in the framework of effective field theory (EFT) are discussed. Using (i) the report of polarized MeV emission from GRB021206 and (ii) the…

We study Horava-Lifshitz gravity in the presence of a scalar field. When the detailed balance condition is implemented, a new term in the gravitational sector is added in order to maintain ultraviolet stability. The four-dimensional theory…

Both projectable and non-projectable versions of Horava-Lifshitz gravity face serious challenges. In the non-projectable version, the constraint algebra is seemingly inconsistent. The projectable version lacks a local Hamiltonian…

Observations of the multi-TeV spectra of the nearby BL objects Mkn 421 and Mkn 501 exhibit the high energy cutoffs predicted to be the result of intergalactic annihilation interactions, primarily with infrared photons having a flux level as…

A proposal for a power-counting renormalizable theory of quantum gravity at a Lifshitz point was recently put forth by Horava (arXiv:0901.3775), and has been since dubbed as Horava-Lifshitz gravity. The theory explicitly breaks Lorentz…

We study perturbations of a scalar field cosmology in Horava-Lifshitz gravity, adopting the most general setup without detailed balance but with the projectability condition. We derive the generalized Klein-Gordon equation, which is…

We calculate the decay width of the photon splitting into three photons in a model of quantum electrodynamics with broken Lorentz invariance. We show that this process can lead to a cut-off in the very-high-energy part of a photon spectra…

The recent discovery of day-long gamma-ray flares in the Crab Nebula, presumed to be synchrotron emission by PeV (10^{15} eV) electrons in milligauss magnetic fields, presents a strong challenge to particle acceleration models. The observed…

We present a fully nonlinear study of long wavelength cosmological perturbations within the framework of the projectable Horava-Lifshitz gravity, coupled to a single scalar field. Adopting the gradient expansion technique, we explicitly…

In this work we have used a Ho\v{r}ava-Lifshitz scaling to rewrite a Lorentz-violating higher-order derivative electrodynamics controlled by a background four-vector $n_{\mu}$. The photon propagator was obtained and we have analyzed the…

In the Horava-Lifshitz theory of quantum gravity, two conditions -- detailed balance and projectability -- are usually assumed. The breaking of projectability simplifies the theory, but it leads to serious problems with the theory. The…