arXiv research

Authors create déjà vu links in Legendrian geometry.

We construct normal forms for Lorentzian metrics on Engel distributions under the assumption that abnormal curves are timelike future directed Hamiltonian geodesics. Then we indicate some cases in which the abnormal timelike future directed curve initiating at the origin is geometrically optimal. We also give certain e…

The mass of asymptotically hyperbolic ends and manifolds is analyzed.

We show that if $(\mathbb{T}^{2},g)$ is a class A Lorentzian 2-torus with timelike poles, then there exists a Lipschitz foliation by complete future-directed timelike geodesics with any pre-assigned asymptotic direction in the interior of the stable time cone. This is done by constructing certain $C^{1,1}$ solutions to…

We prove that the topology, smooth structure, and metric of a compact Lorentzian manifold with boundary is uniquely determined by data at the boundary. The data consists of the lengths and directions of future-directed once-broken geodesics connecting points on the boundary, which are first timelike and then lightlike.…

New topology defined from spacetime paths, reconstructing spacetime structure.

We consider examples of the $\mathbb H$-type groups with the natural horizontal distribution generated by the commutation relations of the group. In the contrast with the previous studies we furnish the horizontal distribution with the Lorentzian metric, which is nondegenerate metric of index 1 instead of a positive de…

Develops optimal transport in Lorentzian spaces with synthetic curvature bounds.

The paper extends Reshetnyak's theorem to Lorentzian length spaces with upper curvature bounds.

Study baryogenesis in conformally flat spacetimes using causal fermion systems.

Recent results on the maximization of the charged-particle action I in a globally hyperbolic spacetime are discussed and generalized. We focus on the maximization of I over a given causal homotopy class C of curves connecting two causally related events x_0 <= x_1. Action I is proved to admit a maximum on C, and also o…

Establishes a Lorentzian Lasry-Lions regularization theorem for functions on globally hyperbolic spacetimes.

New loops found in universe's timeline, challenging traditional time direction.

This article provides the first procedure for computing a fully data-dependent interval that traps the mixing time $t_{\text{mix}}$ of a finite reversible ergodic Markov chain at a prescribed confidence level. The interval is computed from a single finite-length sample path from the Markov chain, and does not require t…

Machine learning models have become more and more complex in order to better approximate complex functions. Although fruitful in many domains, the added complexity has come at the cost of model interpretability. The once popular k-nearest neighbors (kNN) approach, which finds and uses the most similar data for reasonin…

Study of timelike surfaces in Minkowski space with specific geometric properties.

In this paper, using the classifications of timelike and spacelike ruled surfaces, we study the Mannheim offsets of timelike ruled surfaces in Minkowski 3-space. Firstly, we define the Mannheim offsets of a timelike ruled surface by considering the Lorentzian casual character of the offset surface. We obtain that the M…

Paper classifies timelike Bonnet surfaces in Lorentzian 3-manifolds.

In this paper, we introduce the dual geodesic trihedron (dual Darboux frame) of a timelike ruled surface. By the aid of the E. Study Mapping, we consider timelike ruled surfaces as dual hyperbolic spherical curves and define the Mannheim offsets of timelike ruled surfaces by means of dual Darboux frame. We obtain the r…

The study proves timelike Ricci bounds for low regularity spacetimes using optimal transport.

Timelike curvature and Brunn-Minkowski inequality linked in non-smooth spacetimes.

Surveying nonparametric inference with shape constraints, past and future.

This study examines geometric properties and offsets of slant timelike-ruled surfaces.

The study classifies timelike meridian surfaces in Minkowski 4-space.

A celebrated result due to Poincaré affirms that a closed non-degenerate minimizing geodesic $γ$ on an oriented Riemannian surface is hyperbolic. Starting from this classical theorem, our first main result is a general instability criterion for timelike and spacelike closed semi-Riemannian geodesics on a (non)oriented …

The paper studies timelike loxodromes on specific Lorentzian helicoidal surfaces.

Paper proves timelike minimal surfaces with any number of ends exist.

Timelike geometry of spherical simplices is shown to be isometric to vector spaces.

Timelike Thomsen surfaces are timelike minimal surfaces that are also affine minimal. In this paper, we make use of both the Lorentz conformal coordinates and the null coordinates, and their respective representation theorems of timelike minimal surfaces, to obtain a complete global classification of these surfaces and…

The paper proves properties of Lipschitz spacetimes with bounded Ricci curvature.

Timelike curves in Lorentzian length spaces have a total curvature notion that agrees with smooth curves.

New method finds closed timelike geodesics on Lorentzian manifolds.

We introduce a new approach to the study of timelike minimal surfaces in the Lorentz-Minkowski space through a split-complex representation formula for this kind of surface. As applications, we solve the Björling problem for timelike surfaces and obtain interesting examples and related results. Using the Björling repre…

Study timelike meridian surfaces in Minkowski 4-space with specific properties.

Study timelike minimal surfaces in Heisenberg group using harmonic maps.

Study minimal timelike surfaces in 3D Lorentz-Minkowski space using holomorphic functions.

Defines timelike ideal boundary for non-positively curved Lorentzian spaces.

Constructs Lorentzian harmonic maps and associated timelike surfaces.

Paper studies singularities of timelike minimal surfaces in Minkowski 3-space.

In this paper, it is proved that, no special timelike Frenet curve is a Bertrand curve in $\mathbb{E}_2^4$ and also, in $\mathbb{E}_ν^{n+1}$ $({n \ge 3})$, such that the notion of Bertrand curve is definite only in $\mathbb{E}_1^2$ and $\mathbb{E}_1^3$. Therefore, a generalization of timelike Bertrand curve is defined…

Synthetic splitting theorem for Lorentzian spaces with non-negative curvature.

New parametrizations for minimal timelike surfaces discovered.

Isophote comprises a locus of the surface points whose normal vectors make a constant angle with a fixed vector. In this paper, isophote curves are studied on timelike surfaces in Minkowski 3-space E31. The axises of spacelike and timelike isophote curves are found via their Darboux frames. Subsequently, the relationsh…

In this paper, we investigate timelike slant helix in $S_{1}^{2}$ and we obtain parametric equation of timelike slant helix in $S_{1}^{2}$. Also related examples and their illustrations are given.

The study introduces hyperbolic angles in Lorentzian spaces and characterizes curvature bounds.

The aim of this paper is to present a new perspective on the generation of developable trajectory ruled surfaces in Minkowski 3-space. Involute trajectory ruled surfaces generated by the Frenet trihedron, moving along spacelike involutes of a given timelike space curve, is stated according to Lorentzian timelike angle …

We define a new type of transformation for Lorentzian manifolds characterized by mapping every causal future-directed vector onto a causal future-directed vector. The set of all such transformations, which we call causal symmetries, has the structure of a submonoid. Some of their properties are investigated and we give…

Using techniques of integrable systems, we study a Weierstrass representation formula for timelike surfaces with prescribed mean curvature in Minkowski 3-space. It is shown that timelike minimal surfaces are obtained by integrating a pair of Lorentz holomorphic and Lorentz antiholomorphic null curves in Minkowski 3-spa…