Parity Violating Metric-Affine Gravity Theories

宇称破坏引力子非高斯性的新形态

New shape of parity-violating graviton non-Gaussianity

本文证明德西特对称性下的α真空可通过Bogoliubov变换产生宇称破坏张量非高斯性，并发现其双谱在扁平构型中达到峰值的新形态，且振幅可被指数增强。

A simple parity violating gravity model without ghost instability

In this paper we consider a parity violating gravity model without higher derivatives, thus ghost free. This model is constructed from the tetrad and its derivatives and coupled to a dynamical scalar field, like axion. It can be reduced from the Nieh-Yan term within the framework of teleparallel gravity. We apply this model to cosmology and investigate its consequences on cosmological perturbation theory. We find that the coupled dynamical scalar field lost its independent dynamics at the linear order and the parity violating term itself behaves like a viscosity. For gravitational waves, this …

Gravitational Wave Signals from Finite Size Effects in Spinning Binary Inspirals Including Parity Violating Constituents

We generalize the world line EFT formalism to account for parity violating finite size effects. Results are presented for potentials and radiating moments of a binary inspiral for the parity conserving sector, and agreement is found with, previous calculations. Furthermore, we generate new results in this sector, calculating the current quadrupole moment induced by finite size gravitomagnetic effects. We also present novel results for parity violating sources, which might be due to beyond standard model physics, and show that they generate GW signals with the unique signature that the current-…

Parity violating Friedmann Universes

We revisit models, within the Einstein-Cartan theory, where the cosmological constant $Λ$ is promoted to a variable, at the cost of allowing for torsion even in the absence of spinors. We remark that some standard notions about FRW Universes collapse in these theories, most notably spatial homogeneity and isotropy may now co-exist with violations of parity invariance. The parity violating solutions have non-vanishing Weyl curvature even within FRW models. The presence of parity violating torsion opens up the space of possible such theories with relevant FRW modifications: in particular the Pon…

带有破坏宇称项的对称遥平行引力中的标量诱导引力波

Scalar induced gravitational waves in symmetric teleparallel gravity with a parity-violating term

本文研究了带有破坏宇称项的对称遥平行引力中的标量诱导引力波，发现破坏宇称项贡献可忽略，但联络扰动产生多峰结构，使其区别于广义相对论。

Parity Violating Gravitational Coupling Of Electromagnetic Fields

A manifestly gauge invariant formulation of the coupling of the Maxwell theory with an Einstein Cartan geometry is given, where the space time torsion originates from a massless Kalb-Ramond field augmented by suitable U(1) Chern Simons terms.We focus on the situation where the torsion violates parity, and relate it to earlier proposals for gravitational parity violation.

Macroscopic parity violating effects and 3He-A

We discuss parity violating effects in relativistic quantum theory and their analogues in effective field theory of superfluid 3He-A. A mixed axial-gravitational Chern-Simons term in the relativistic effective action and its condensed matter analog are responsible for the chiral fermion flux along the rotation axis of the heat bath in relativistic system and for the unusual Omega-odd dependence of the zero-temperature density of the normal component on the rotation velocity in 3He-A.