Related papers: Graviton propagator as a tool to test spinfoam mod…
I discuss progress towards "bootstrapping" a Lorentz-violating gravity theory: namely, extending a linear Lorentz-violating theory of a rank-2 tensor to a non-linear theory by coupling this field to its own stress-energy tensor.
We perform a covariant constraint analysis of massive gravity valid for its entire parameter space, demonstrating that the model generically propagates five degrees of freedom; this is also verified by a new and streamlined Hamiltonian…
In this work, we explicitly evaluate the gauge propagator of the Maxwell theory supplemented by the CPT-even term of the SME. First, we specialize our evaluation for the parity-odd sector of the tensor $W_{\mu \nu \rho \sigma}$,\ using a…
When it comes to searches for extensions to general relativity, large efforts are being dedicated to accurate predictions for the power spectrum of density perturbations. While this observable is known to be sensitive to the gravitational…
We point out that in certain four-dimensional extensions of general relativity constructed within the Palatini formalism stable self-gravitating objects with a discrete mass and charge spectrum may exist. The incorporation of nonlinearities…
We discuss fermion coupling in the framework of spinfoam quantum gravity. We analyze the gravity-fermion spinfoam model and its fermion correlation functions. We show that there is a spinfoam analog of PCT symmetry for the fermion fields on…
We study branes residing in infinite volume space and of finite extent in the transverse directions. We calculate the graviton propagator in the harmonic gauge both inside and outside the brane and discuss its dependence on the thickness of…
In this work, within the framework of path integral Monte Carlo, we construct a pseudo-fermion propagator by replacing the original fermionic determinant with its absolute value. This modified propagator defines an auxiliary system free…
Robust adaptive model predictive control (RAMPC) is a novel control method that combines robustness guarantees with respect to unknown parameters and bounded disturbances into a model predictive control scheme. However, RAMPC has so far…
The ability to simulate and predict the outcome of contacts is paramount to the successful execution of many robotic tasks. Simulators are powerful tools for the design of robots and their behaviors, yet the discrepancy between their…
We obtain sharp decay estimates and asymptotics for small solutions to the one-dimensional Klein-Gordon equation with constant coefficient cubic and spatially localized, variable coefficient cubic nonlinearities. Vector-field techniques to…
In this report I consider the cosmology of KK gravitinos in models with extra dimensions, in particular in connection with the known non--standard high energy regime of expansion which is associated with them. The main result is that the…
We perform a linear stability analysis of dynamical, quadratic gravity in the high-frequency, geometric optics approximation. This analysis is based on a study of gravitational and scalar modes propagating on spherically-symmetric and…
We examine the accuracy of the quasi-static approximation and a parametric form commonly employed for evolving linear perturbations in f(R) gravity theories and placing cosmological constraints. In particular, we analyze the nature and the…
We show that the new type of "non-metric" gravity theories introduced independently by Bengtsson and Krasnov can in fact be reexpressed explicitely as a metrical theory coupled to an auxiliary field. We unravel why such theories possess…
Scalar-tensor gravity theories with a nonminimal Gauss-Bonnet coupling typically lead to an anomalous propagation speed for gravitational waves, and have therefore been tightly constrained by multimessenger observations such as…
We illustrate preliminary results on the gluon propagator computed in generic covariant lattice gauges in the quenched approximation with the Wilson action. We have applied a recently proposed procedure to fix a generic covariant gauge on…
We address the problem of Gribov copies in lattice QCD. The gluon propagator is computed, in the Landau gauge, using 302 ($\beta = 5.8$) $12^4$ configurations gauge fixed to different copies. The results of the simulation shows that: i) the…
We consider effective action for the Einstein gravity and show that dressed mean fields are actual variables of the effective action. Kernels of this effective action expressed in terms of dressed effective fields are constituent parts of…
Models predicting the existence of extra spatial dimensions offer compelling and novel solutions to outstanding problems of the Standard Model. In such models, our universe exists on a 4 dimensional brane embedded in a larger dimensional…