Editorial for the Special Issue "Progress in Group Field Theory and Related Quantum Gravity Formalisms"

Editorial: Coarse graining in quantum gravity -- Bridging the gap between microscopic models and spacetime physics

The Renormalization Group encodes three concepts that could be key to accelerate progress in quantum gravity. First, it provides a micro-macro connection that could connect microscopic spacetime physics to phenomenology at observationally accessible scales. Second, it enables a search for universality classes that could link diverse quantum-gravity approaches and allow us to discover that distinct approaches could encode the same physics in mathematically distinct structures. Third, it enables the emergence of symmetries at fixed points of the Renormalization Group flow, providing a way for sp…

General Relativity à la string: a progress report

Preliminary results on a canonical formulation of general relativity based on an analogy with the string model of elementary particles are presented. Rather than the metric components, the basic fields of the formalism are taken to be the functions describing the embedding of four dimensional spacetime in a ten or possibly higher dimensional manifold. So far, the main drawback of the formalism is that the generator of normal deformations ("fourth constraint") cannot be written down in closed form. The present approach is compared and contrasted with the usual one and with the canonical descrip…

Weyl引力电磁学中的牛顿势

Newtonian Potential in Weyl Gravitoelectromagnetism

本文研究Weyl引力电磁学的规范结构，将其应用于张量场介导的巴巴散射，推导零温极限下的牛顿势，发现高温下该势会因热场动力学效应被抑制，呈现热屏蔽机制。

在Palatini形式中具有非最小耦合本体标量场的厚膜

Thick brane in Palatini formalism with a non-minimally coupled bulk scalar field

本文在Palatini形式中研究了具有非最小耦合本体标量场的厚膜，通过解析解和稳定性分析，揭示了引力局域化和四维引力恢复的机制。

Generalizing Starobinskii's Formalism to Yukawa Theory & to Scalar QED

During inflation quantum effects from massless, minimally coupled scalars and gravitons can be strengthened so much that perturbation theory breaks down. To follow the subsequent evolution one must employ a nonperturbative resummation. Starobinski\uı has developed such a technique for simple scalDuring inflation quantum effects from massless, minimally coupled scalars and gravitons can be strengthened so much that perturbation theory breaks down. To follow the subsequent evolution one must employ a nonperturbative resummation. Starobinski\uı has developed such a technique for simple scalar the…

Recent progress on the description of relativistic spin: vector model of spinning particle and rotating body with gravimagnetic moment in General Relativity

We review the recent results on development of vector models of spin and apply them to study the influence of spin-field interaction on the trajectory and precession of a spinning particle in external gravitational and electromagnetic fields. The formalism is developed starting from the Lagrangian variational problem, which implies both equations of motion and constraints which should be presented in a model of spinning particle. We present a detailed analysis of the resulting theory and show that it has reasonable properties on both classical and quantum level. We describe a number of applica…