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We consider Lorentzian correlation functions in theories with non-relativistic Schrodinger symmetry. We employ the method developed by Skenderis and van Rees in which the contour in complex time defining a given correlation function is…

High Energy Physics - Theory · Physics 2009-11-13 Robert G. Leigh , Nam Nguyen Hoang

We derive simplicity constraints for the quantization of general Lorentzian 4-geometries. Our method is based on the correspondence between coherent states and classical bivectors and the minimization of associated uncertainties. For…

General Relativity and Quantum Cosmology · Physics 2011-01-19 Florian Conrady , Jeff Hnybida

We employ the methods of discrete (Lorentzian) Regge calculus for analysing Lorentzian quantum cosmology models with a special focus on discrete analogues of the no-boundary proposal for the early universe. We use a simple 4-polytope, a…

General Relativity and Quantum Cosmology · Physics 2022-01-24 Bianca Dittrich , Steffen Gielen , Susanne Schander

We derive a dynamical bound on the propagation of correlations in local random quantum circuits - lattice spin systems where piecewise quantum operations - in space and time - occur with classical probabilities. Correlations are quantified…

Quantum Physics · Physics 2017-05-15 Siddhartha Santra , Radhakrishnan Balu

We prove that all functions obeying the Kramers-Kronig relations can be approximated as superpositions of Lorentzian functions, to any precision. As a result, the typical text-book analysis of dielectric dispersion response functions in…

Optics · Physics 2013-10-16 Christopher A. Dirdal , Johannes Skaar

The relativistic fermion-antifermion bound state vector potential of constraint theory is calculated, in perturbation theory, by means of the Lippmann-Schwinger type equation that relates it to the scattering amplitude. Leading…

High Energy Physics - Phenomenology · Physics 2009-10-28 H. Jallouli , H. Sazdjian

Starting from the Lorentzian inversion formula, we derive a dispersion relation which computes a four-point function in 1d CFTs as an integral over its double discontinuity. The crossing symmetric kernel of the integral is given explicitly…

High Energy Physics - Theory · Physics 2024-10-16 Davide Bonomi , Valentina Forini

The complex critical points are analyzed in the 4-dimensional Lorentzian Engle-Pereira-Rovelli-Livine (EPRL) spinfoam model in the large-$j$ regime. For the 4-simplex amplitude, taking into account the complex critical point generalizes the…

General Relativity and Quantum Cosmology · Physics 2023-08-02 Muxin Han , Hongguang Liu , Dongxue Qu

We calculate a class of two-point boundary correlators in 2D quantum gravity using its microscopic realization as loop gas on a random surface. We find a perfect agreement with the two-point boundary correlation function in Liouville…

High Energy Physics - Theory · Physics 2010-04-05 Ivan K. Kostov

The Einstein-Proca action is known to have asymptotically locally Lifshitz spacetimes as classical solutions. For dynamical exponent z=2, two-point correlation functions for fluctuations around such a geometry are derived analytically. It…

High Energy Physics - Theory · Physics 2015-06-17 Tobias Zingg

I introduce a family of closeness functions between causal Lorentzian geometries of finite volume and arbitrary underlying topology. When points are randomly scattered in a Lorentzian manifold, with uniform density according to the volume…

General Relativity and Quantum Cosmology · Physics 2015-06-25 Luca Bombelli

The fusion coefficients from SO(3) to SO(4) play a key role in the definition of spin foam models for the dynamics in Loop Quantum Gravity. In this paper we give a simple analytic formula of the EPRL fusion coefficients. We study the large…

General Relativity and Quantum Cosmology · Physics 2013-04-30 Emanuele Alesci , Eugenio Bianchi , Elena Magliaro , Claudio Perini

A certain operator $\T=\int_{\SL}\dd g\, Y^{\dagger}gY$ can be found in various Lorentzian EPRL calculations. The properties of this operator has been studied here in large $j$ limit. The leading order of $\T$ is proportional to the…

General Relativity and Quantum Cosmology · Physics 2013-07-19 Jacek Puchta

We describe here some new results concerning the Lorentzian Barrett-Crane model, a well-known spin foam formulation of quantum gravity. Generalizing an existing finiteness result, we provide a concise proof of finiteness of the partition…

General Relativity and Quantum Cosmology · Physics 2009-11-11 J. Wade Cherrington

In $\mathcal{N}=1$ superconformal theories in four dimensions the two-point function of superconformal multiplets is known up to an overall constant. A superconformal multiplet contains several conformal primary operators, whose two-point…

High Energy Physics - Theory · Physics 2018-03-08 Daliang Li , Andreas Stergiou

The two purposes of the paper are (1) to present a regularization of the self-field of point-like particles, based on Hadamard's concept of ``partie finie'', that permits in principle to maintain the Lorentz covariance of a relativistic…

General Relativity and Quantum Cosmology · Physics 2009-10-31 Luc Blanchet , Guillaume Faye

In two-dimensional lattice fermion model a determinant representation for the two-point correlation function of the twist field in the disorder phase is obtained. This field is defined by twisted boundary conditions for lattice fermion…

High Energy Physics - Theory · Physics 2007-05-23 Anatolij I. Bugrij , Vitalij N. Shadura

We show that the normalized Lorentzian state sum is finite on any triangulation. It thus provides a candidate for a perturbatively finite quantum theory of general relativity in four dimensions with Lorentzian signature.

General Relativity and Quantum Cosmology · Physics 2007-05-23 Louis Crane , Alejandro Perez , Carlo Rovelli

We propose a formulation of a Lorentzian quantum geometry based on the framework of causal fermion systems. After giving the general definition of causal fermion systems, we deduce space-time as a topological space with an underlying causal…

Mathematical Physics · Physics 2014-01-28 Felix Finster , Andreas Grotz

In a conformal field theory, two and three-point functions of scalar operators and conserved currents are completely determined, up to constants, by conformal invariance. The expressions for these correlators in Euclidean signature are long…

High Energy Physics - Theory · Physics 2020-02-19 Teresa Bautista , Hadi Godazgar