arXiv research

Study on Bertrand lightcone framed curves in Lorentz-Minkowski 3-space.

Study on focal surfaces of lightcone framed surfaces in Lorentz-Minkowski 3-space.

Study of lightcone framed surfaces in Lorentz-Minkowski 3-space, focusing on curvature behavior.

We define the notions of $S_t^1\times S_s^1$-valued lightcone Gauss maps, lightcone pedal surface and Lorentzian lightcone height function of Lorentzian surface in semi-Euclidean 4-space and established the relationships between singularities of these objects and geometric invariants of the surface as applications of s…

Past lightcones of certain points in globally hyperbolic spacetimes determine the entire spacetime.

Study of null mean curvature flow on de Sitter lightcone, related to 2d-Ricci flow.

Paper proves isoperimetric inequality for Minkowski spacetime.

Proves estimate similar to De Lellis-Müller on Minkowski lightcone.

On any spacelike surface in a lightcone of four dimensional Lorentz-Minkowski space a distinguished smooth function is considered. It is shown how both extrinsic and intrinsic geometry of such a surface is codified by this function. The existence of a local maximum is assumed to decide when the spacelike surface must b…

Constructs foliations of lightcones using surfaces of constant spacetime mean curvature.

Paper proves uniqueness of specific spacetime surfaces in a lightcone.

We introduce the totally absolute lightcone curvature for a spacelike submanifold with general codimension and investigate global properties of this curvature. One of the consequences is that the Chern-Lashof type inequality holds. Then the notion of lightlike tightness is naturally induced.

New perspective on Ricci flow on spheres using Minkowski spacetime.

Study shows constant curvature convex hypersurfaces on hyperboloids are parts of hyperboloids.

Study on stability of surfaces in null cones under area-preserving variations.

The problem of quasilocal energy has been extensively studied mainly in four dimensions. Here we report results regarding the quasilocal energy in spacetime dimension $n\geq 4$. After generalising three distinct quasilocal energy definitions to higher dimensions under appropriate assumptions, we evaluate their small sp…

Any 2-dim Riemannian manifold with spherical topology can be embedded isometrically into a lightcone of the Minkowski spacetime. We apply this fact to give a proof of the Kazdan-Warner identity.

We prove existence and uniqueness of entire spacelike hypersurfaces in the Minkowski space with prescribed negative scalar curvature, and with given values at infinity which stay at a bounded distance of a lightcone.

Klainerman, Luk and Rodnianski derived an anisotropic criterion for formation of trapped surfaces in vacuum, extending the original trapped surface formation theorem of Christodoulou. The effort to understand their result led us to study the intersection of a hyperplane with a lightcone in the Minkowski spacetime. For …

We prove a rigidity of the lightcone in Minkowski space. It is essentially the unique space endowed with a degenerate Riemannian metric, of lightlike type, and supporting an isometric non-proper action of a semi-simple group.

A spacelike surface in four-dimensional Lorentz-Minkowski spacetime through the lightcone has a meaningful lightlike normal vector field $η$. Several sufficient assumptions on such a surface with non-degenerate $η$-second fundamental form are established to prove that it must be a totally umbilical round sphere. With t…

We prove effective uniformization for nearly round 2-spheres and investigate their stability.

Generalizes Fermat's principle for wave propagation in cone structures.

To study spacelike surfaces in the Lorentz-Minkowski space $\Bbb R^{4}_1,$ we construct a pair of maps whose values are in the lightcone, called $\mathfrak l_r^{\pm}$-Gauss maps. We can use these maps to study umbilical spacelike surfaces and find parametrizations of spacelike surfaces of revolution of hyperbolic and …

We first describe the numerical invariants attached to the second fundamental form of a spacelike surface in four-dimensional Minkowski space. We then study the configuration of the nu-principal curvature lines on a spacelike surface, when the normal field nu is lightlike (the lightcone configuration). Some observation…

In a joint work with Saji, the second and the third authors gave an intrinsic formulation of wave fronts and proved a realization theorem of wave fronts in space forms. As an application, we show that the following four objects are essentially same; * conformally flat n-manifolds (n>=3) with admissible singular points …

The paper studies helicoidal surfaces of non-lightlike frontals in Lorentz-Minkowski 3-space.

Gauging procedure constructs lagrangians for carrollian gravity.

Introduces hyperbolic generalized framed surfaces and their properties.

Study of spacelike discs in Minkowski cones, proving self-similar expansion.

A Laguerre geometric local characterization is given of L-minimal surfaces and Laguerre deformations (T-transforms) of L-minimal isothermic surfaces in terms of the holomorphicity of a quartic and a quadratic differential. This is used to prove that, via their Laguerre Gauss maps, the T-transforms of L-minimal isotherm…

Sharp Sobolev inequality on circle proven with Lorentz invariance.

In General Relativity the metric can be recovered from the structure of the lightcones and a measure giving the volume element. Since the causal structure seems to be simpler than the Lorentzian manifold structure, this suggests that it is more fundamental. But there are cases when seemingly healthy causal structure an…

New spaces at infinity identified for Minkowski spacetime.

The study characterizes surfaces with specific harmonic properties in pseudo-conformal geometry.

Compactifies Minkowski space using unitary matrices.

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…

This paper is devoted to the study of the singularity phenomenon of timelike extremal hypersurfaces in Minkowski spacetime $\mathbb{R}^{1+3}$. We find that there are two explicit lightlike self-similar solutions to a graph representation of timelike extremal hypersurfaces in Minkowski spacetime $\mathbb{R}^{1+3}$, the …

21cmEMU speeds up EoR simulations by 10^4x, predicting key observables with sub-percent accuracy.

The paper proves rigidity theorems for space-like hypersurfaces in Minkowski space.