Research
On-device research index

arXiv research

A locally-built, LLM-digested index of recent arXiv papers in quant finance, geometry/topology, and statistical ML — keyword search served straight from SQLite on this machine.

168,878 papers · 148 categories

Trend · papers per month

8.3%16.7%25.0%33.3% · Sep 199519922001200920172026
48 results for Lorentzian angles

In Lorentzian geometry, limited definition of angles restricts the use of angle bisectors in study of triangles. This paper redefines angle bisectors so that they can be used to study attributes of triangles. Using the new definition, this paper investigates the existence of the incenter and the isogonal conjugate of a…

2014-04-24abs ↗pdf ↗

Study on null hypersurfaces with constant angle in Lorentzian manifolds.

problem Understanding constant angle null hypersurfaces in Lorentzian manifolds.
method Introduced constant angle null hypersurfaces, analyzed with respect to a given ambient vector field, and provided classification results.
result Null hypersurfaces have a canonical principal direction when the vector field is closed and conformal.

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

problem Characterizing timelike curvature bounds in Lorentzian spaces.
method Synthetic geometric framework of Lorentzian (pre-)length spaces, introduction of hyperbolic angles, and angle monotonicity condition.
result Characterization of timelike curvature bounds with an angle monotonicity condition.

Study classifies helix surfaces in Lorentzian Heisenberg group.

problem Classifying helix surfaces in Lorentzian Heisenberg group.
method Complete description of ambient space geometry, classification of minimal and CMC helix surfaces, investigation of constant angle surfaces.
result Explicit parametrizations of minimal and CMC helix surfaces in $\htt$.

In this paper, we define and, then, we characterize constant angle spacelike and timelike surfaces in the three-dimensional Heisenberg group, equipped with a 1-parameter family of Lorentzian metrics. In particular, we give an explicit local parametrization of these surfaces and we produce some examples.

2017-02-19abs ↗pdf ↗

Study on Lorentzian spaces with curvature bounds, proving comparison theorems.

problem Understanding curvature bounds in Lorentzian spaces.
method Introduced normalized angle for Lorentzian pre-length spaces, proving comparison theorems.
result Established local Lorentzian Toponogov theorem and Alexandrov convexity property.

In this paper we study slant submanifolds of Lorentzian almost contact manifolds. We have taken the submanifold as a space like and then defined the slant angle on a submanifold and thus we extended the results of A. Lotta (Slant submanifolds in contact geometry [8]) and M. A. Khan et. al. (Slant submanifolds of Lorent…

2012-04-27abs ↗pdf ↗

We first define a complex angle between two oriented spacelike planes in 4-dimensional Minkowski space, and then study the constant angle surfaces in that space, i.e. the oriented spacelike surfaces whose tangent planes form a constant complex angle with respect to a fixed spacelike plane. This notion is the natural Lo…

2019-03-04abs ↗pdf ↗

In this work, we study helix spacelike and timelike surfaces in the Lorentzian Berger sphere $\s_{\varepsilon}^3$, that is the three-dimensional sphere endowed with a 11-parameter family of Lorentzian metrics, obtained by deforming the round metric on $\s^3$ along the fibers of the Hopf fibration $\s^3\to \s^2({1}/{2}…

2017-05-29abs ↗pdf ↗

Paper proves rigidity of de-Sitter tori with conical singularities.

problem Global rigidity of de-Sitter tori with singularities.
method Introduced constant curvature Lorentzian surfaces with conical singularities and proved rigidity via topological dynamics.
result De-Sitter tori with a single singularity are determined by their lightlike bi-foliation.

Synthetic approach to conformal transformations in metric and Lorentzian spaces.

problem Defining consistent conformal transformations in spaces of low regularity.
method Introducing conformal transformations in metric and Lorentzian spaces, focusing on Lorentzian pre-length spaces.
result Established a consistent notion of conformal length and proved its properties.

Study laws of cosines and sines for hyperbolic shapes with ideal vertices.

problem Formulating trigonometric laws for shapes with ideal vertices in hyperbolic geometry.
method Using hyperboloid model and Lorentzian geometry, establishing laws for quadrilaterals, pentagons, and partially truncated tetrahedra.
result Transversal lengths of partially truncated tetrahedra depend only on internal edge lengths at ideal vertices.

We consider compact hypersurfaces in an (n+1)(n+1)-dimensional either Riemannian or Lorentzian space Nn+1N^{n+1} endowed with a conformal Killing vector field. For such hypersurfaces, we establish an integral formula which, especially in the simpler case when N=Mn×RN=M^n\times R is a product space, allows us to derive some inte…

2009-06-11abs ↗pdf ↗

In this paper, we classify all the orientable hyperbolic 5-manifolds that arise as a hyperbolic space form H5/ΓH^5/Γ where ΓΓ is a torsion-free subgroup of minimal index of the congruence two subgroup Γ25Γ^5_2 of the group Γ5Γ^5 of positive units of the Lorentzian quadratic form x12+...+x52x62x_1^2+...+x_5^2-x_6^2. We also show that…

2003-08-13abs ↗pdf ↗

Using global considerations, Mess proved that the moduli space of globally hyperbolic flat Lorentzian structures on S×RS\times\mathbb{R} is the tangent bundle of the Teichmüller space of SS, if SS is a closed surface. One of the goals of this paper is to deepen this surprising occurrence and to make explicit the relat…

2015-01-20abs ↗pdf ↗

In this work we study spacelike hypersurfaces immersed in spatially open standard static spacetimes with complete spacelike slices. Under appropriate lower bounds on the Ricci curvature of the spacetime in directions tangent to the slices, we prove that every complete CMC hypersurface having either bounded hyperbolic a…

2019-01-25abs ↗pdf ↗

In this article we study minimal flat Lorentzian surfaces in Lorentzian complex space forms. First we prove that, for minimal flat Lorentzian surfaces in a Lorentzian complex form, the equation of Ricci is a consequence of the equations of Gauss and Codazzi. Then we classify minimal flat Lorentzian surfaces in the Lore…

2013-07-15abs ↗pdf ↗

Study of a series of Lorentzian structures on SL(2,R) with SO(1,1) symmetry.

problem Global optimality of extremal trajectories in a series of Lorentzian structures.
method Analysis of a one-parametric series of left-invariant Lorentzian structures on SL(2,R) with SO(1,1) symmetry.
result Properties of the Lorentzian structures deform to those of the sub-Lorentzian structure in a limit case.

Study left-invariant Codazzi tensors and harmonic curvature on Lorentzian Lie groups.

problem Characterize left-invariant Codazzi tensors and harmonic curvature on Lorentzian Lie groups.
method Analyze left-invariant Codazzi tensors and harmonic curvature on Lorentzian Lie groups, classify Lie algebras and groups.
result New results on left-invariant Lorentzian metrics with harmonic curvature and non-parallel Ricci operator.

It is shown how one can apply the classification of the holonomy algebras of Lorentzian manifolds to solve some problems. In particular, a new proof to the classification of Lorentzian manifolds with recurrent curvature tensor is given; the classification of two-symmetric Lorentzian manifolds is explained; conformally …

2010-11-30abs ↗pdf ↗

Study gluing of Lorentzian length spaces and their causal ladder properties.

problem Compatibility of Lorentzian amalgamation with length space properties.
method Conditions for gluing Lorentzian length spaces and criteria for causal ladder preservation.
result Gluing of Lorentzian length spaces yields again a Lorentzian length space under certain conditions.

Defines doubling conditions for Lorentzian spaces linked to curvature bounds.

problem Relating doubling conditions to curvature bounds in Lorentzian geometry.
method Defines doubling conditions using chronological diamonds and proves implications with timelike curvature bounds.
result Relates doubling to curvature bounds in Lorentzian geometry.

The study proves a transverse diameter theorem for Lorentzian foliations.

problem Understanding the geometry of foliations in Lorentzian spacetimes.
method Developed a novel causality structure on leaf spaces via transverse Lorentzian geometry.
result Derived a transverse diameter theorem for Lorentzian foliations and orbifolds.

Timelike minimal surfaces in Lorentzian Heisenberg group have singular points.

problem Characterizing singularities on timelike minimal surfaces.
method Constructing timelike minimal surfaces as Lorentzian harmonic maps and analyzing their singularities.
result Criteria for cuspidal edges, swallowtails, and cuspidal cross caps are provided.

Defines new metrics for Lorentzian spaces and their convergence.

problem Defining metrics for Lorentzian spaces and their convergence.
method Abstract approach to Lorentzian Gromov-Hausdorff distance and convergence, defining bounded Lorentzian-metric spaces, and proving stability under GH limits.
result GH limits of Lorentzian-metric spaces are isometric and homeomorphic.

Characterizes Lorentzian manifolds embeddable in Minkowski spacetime.

problem Identifying Lorentzian manifolds embeddable in Minkowski spacetime.
method Characterization and proof of embeddability conditions.
result Lorentzian manifolds embeddable in Minkowski spacetime coincide with globally hyperbolic spacetimes.

In this paper, we study the invariant and noninvariant hypersurfaces of (1,1,1) almost contact manifolds, Lorentzian almost paracontact manifolds and Lorentzian para-Sasakian manifolds, respectively. We show that a noninvariant hypersurface of an (1,1,1) almost contact manifold admits an almost product structure. We in…

2009-09-25abs ↗pdf ↗

If an m+2m+2-manifold MM is locally modeled on $\RR^{m+2}$ with coordinate changes lying in the subgroup $G=\RR^{m+2}\rtimes ({\rO}(m+1,1)\times \RR^+)$ of the affine group ${\rA}(m+2)$, then MM is said to be a \emph{Lorentzian similarity manifold}. A Lorentzian similarity manifold is also a conformally flat Lorentzia…

2011-10-09abs ↗pdf ↗