Related papers: New shape for cross-bispectra in Chern-Simons grav…
Parity violation in gravity, if existed, could have important implications, and it is meaningful to search and test the possible observational effects. Chern-Simons modified gravity serves as a natural model for gravitational…
The gravitational memory effects of Chern-Simons modified gravity are considered in the asymptotically flat spacetime. If the Chern-Simons scalar does not directly couple with the ordinary matter fields, there are also displacement, spin…
We consider the Chern--Simons term coupled to the inflaton in the Palatini formulation of general relativity. In contrast to the metric formulation, here the Chern--Simons term affects also the background evolution. We approximately solve…
In this work, we investigate tensor perturbations in a de Sitter background within the framework of Chern-Simons modified gravity. We introduce transverse-traceless perturbations and analyze how the Chern-Simons Cotton tensor induces…
We study the inflationary implications of a novel parity-violating gravity model, which modifies the teleparallel equivalent of general relativity by introducing the Nieh-Yan term coupled to an axion-like field. The parity-violating…
Chern-Simons modified gravity is a string-theory and loop-quantum-gravity inspired effective theory that modifies General Relativity by adding a parity-violating Pontryagin density to the Einstein-Hilbert action multiplied by a coupling…
The tests of parity symmetry in the gravitational interaction is an attractive issue in the gravitational-wave astronomy. In the general theories of gravity with parity violation, one of the fundamental results is that the primordial…
Chern-Simons modified gravity is an effective extension of general relativity that captures leading-order, gravitational parity violation. Such an effective theory is motivated by anomaly cancelation in particle physics and string theory.…
We calculate the scalar-induced gravitational wave energy density in the theory of Ghost Inflation, assuming scale invariance and taking into account both the power spectrum- and trispectrum-induced contributions. For the latter we consider…
We study a model of inflation with multiple pseudo-scalar fields coupled to a $U(1)$ gauge field through Chern-Simons interactions. Because of parity violating interactions, one polarization of the gauge field is amplified yielding to…
The recent discovery of gravitational wave events has offered us unique testbeds of gravity in the strong and dynamical field regime. One possible modification to General Relativity is the gravitational parity violation that gives rise to…
Neutron stars are sensitive laboratories for testing general relativity, especially when considering deviations where velocities are relativistic and gravitational fields are strong. One such deviation is described by dynamical,…
Cosmological correlation functions of inflaton and graviton perturbations are the fundamental observables of early universe cosmology and remain a primary target for observations. In this work, we ask the following question: are these…
A Chern-Simons interaction between a pseudo-scalar field and a U(1) gauge field results in the generation of a chiral gravitational wave background. The detection of this signal is contrasted by the fact that this coupling also generates…
Within the framework of Chern-Simons gravity, a theory that dynamically violates parity, we analyze the power spectrum of gravitational waves in light of the damping effect due to the free streaming relativistic neutrinos and dark fermions.…
It has been found that the primordial non-Gaussianity of the curvature perturbation in the case of non-Bunch-Davies initial states can be enhanced compared with those in the case of the Bunch-Davies one due to the interactions among the…
An alternative scenario about the phenomenology of primordial Universe is k-inflation. According to this concept, inflation can be achieved by nonstandard kinetic term of scalar field, namely the inflaton. In this project we focus on…
We propose a dynamical amplification mechanism for detecting symmetry breaking in black holes through environmentally driven spectral instabilities of quasinormal modes. Focusing on dynamical Chern-Simons gravity as a paradigm for parity…
We consider a model of inflation in which the inflaton field is a rolling axion with a potential which is flat enough to support an intermediate phase of USR inflation. Because of the Chern-Simons interaction, one polarization of the gauge…
The power suppression at largest scale in the CMB TT powerspectrum might imply the occurrence of a pre-inflationary bounce. We calculate the circularly polarized gravitational wave, leaded by the gravitational Chern-Simons term which…