We study the geometry of compact Lorentzian manifolds that admit a somewhere timelike Killing vector field, and whose isometry group has infinitely many connected components. Up to a finite cover, such manifolds are products (or amalgamated products) of a flat Lorentzian torus and a compact Riemannian (resp., lightlike) manifold.

The four Rindler quadrants of a pair of oppositely accelerated frames are identified as a (Lorentzian) Mach-Zehnder interferometer. The Rindler frequency dependence of the interference process is expressed by means of a (Lorentzian) differential cross section. The Rindler frequencies of the waves in the two acccelerated frames can be measured directly by means of a simple inertially moving dete...

We consider an asymptotically flat Lorentzian manifold of dimension (1, 3). An inequality is derived which bounds the Riemannian curvature tensor in terms of the ADM energy in the general case with second fundamental form. The inequality quantifies in which sense the Lorentzian manifold becomes flat in the limit when the ADM energy tends to zero.

Study of five-fold (P even, T odd) correlation in the interaction of slow polarized neutrons with aligned nuclei is a perspective way to test time reversal invariance due to expected enhancement of T violating effects in compound resonances. Possible nuclear targets are discussed which can be aligned both dynamically as well as by ”brute force” method at low temperature. Statistical estimation ...

Aligned and random nanocomposite nanofibrous scaffolds were electrospun from polycaprolactone (PCL), poly (vinyl alcohol) (PVA) and hydroxyapatite nanoparticles (nHA). The morphology and mechanical characteristics of the nanofibers were evaluated using scanning electron microscopy and tensile testing, respectively. Scanning electron microscopy revealed fibers with an average diameter of 123 ± 3...

Quantitative nanoindentation of nominally 7.5 and 600 μm tall vertically aligned carbon nanotube (VACNT) arrays is observed in situ within an SEM chamber. The 7.5 μm array consists of highly aligned and weakly interacting CNTs and deflects similarly to classically defined cylindrical columns, with deformation geometry and critical buckling force well estimated using the Euler-Bernoulli theory. ...

We consider Lorentzian correlation functions in theories with non-relativistic Schrödinger symmetry. We employ the method developed by Skenderis and van Rees in which the contour in complex time defining a given correlation function is associated holographically with the gluing together of Euclidean and Lorentzian patches of spacetimes. This formalism extends appropriately to geometries with Sc...

The asymmetric ABAB-matrix model describes the transfer matrix of threedimensional Lorentzian quantum gravity. We study perturbatively the scaling of the ABAB-matrix model in the neighbourhood of its symmetric solution and deduce the associated renormalization of three-dimensional Lorentzian quantum gravity. pacs: 04.60Gw, 04.20Gz, 04.60Kz, 04.60Nc Presented by J.J. at the Workshop on Random Ge...

We prove that a four-dimensional Lorentzian manifold that is curvature homogeneous of order 3, or CH3 for short, is necessarily locally homogeneous. We also exhibit and classify four-dimensional Lorentzian, CH2 manifolds that are not homogeneous. PACS numbers: 04.20, 02.40 AMS classification scheme numbers: 53C50

This is an informal introduction to stochastic analysis on both Riemanian and Lorentzian manifolds. We review the basics underlying the construction of diffusions on manifolds, highlighting the important differences between the Riemanian and Lorentzian cases. We also discuss a few recent applications which range from biophysics to cosmology.