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.

168,657 papers · 148 categories

Trend · papers per month

23477093 · May 202619922001200920172026
48 results for marginal tubes

We give conditions on a general stress-energy tensor T_{αβ} in a spherically symmetric black hole spacetime which are sufficient to guarantee that the black hole will contain a (spherically symmetric) marginally trapped tube which is eventually achronal, connected, and asymptotic to the event horizon. Price law decay p…

2007-02-19abs ↗pdf ↗

Study proves existence of MOTTs in de Sitter spacetime.

problem Proving existence of marginally outer trapped tubes in de Sitter spacetime.
method Combining results from spacetimes satisfying null convergence condition and properties of CMC surfaces in S3.
result Existence of complete MOTTs with CMC sections in de Sitter spacetime.

Small deformations of marginally (outer) trapped surfaces are considered by using their stability operator. In the case of spherical symmetry, one can use these deformations on any marginally trapped round sphere to prove several interesting results. The concept of 'core' of a black hole is introduced: it is a minimal …

2012-10-13abs ↗pdf ↗

Small deformations of marginally outer trapped surfaces (MOTS) are studied by using the stability operator introduced by Andersson-Mars-Simon. Novel formulae for the principal eigenvalue are presented. A characterization of the many marginally outer trapped tubes (MOTT) passing through a given MOTS is given, and the po…

2012-11-26abs ↗pdf ↗

Weyl's tube formula holds for various cross-sections under symmetry conditions.

problem Can the volume of tubes around submanifolds be calculated for non-round cross-sections?
method Investigated the volume of tubes with general cross-sections D under symmetry conditions.
result The volume of tubes around submanifolds can be calculated for general cross-sections under symmetry conditions.

We solve Einstein vacuum equations in a spacetime region up to the "center" of gravitational collapse. Within this region, we construct a sequence of marginally outer trapped surfaces (MOTS) with areas going to zero. These MOTS form a marginally outer trapped tube (apparent horizon). It emerges from a point and is smoo…

2017-03-01abs ↗pdf ↗

The purpose of the present work is to study (marginally) trapped submanifolds lying in a null hypersurface. Let $(M,g,N)\to\Bm(c)$ be a null hypersurface of a space-time with constant sectional curvature cc, endowed with a Screen Integrable and Conformal rigging NN. The (Marginally) Trapped Submanifolds we are intere…

2017-06-12abs ↗pdf ↗

H. Hotelling proved that in the n-dimensional Euclidean or spherical space, the volume of a tube of small radius about a curve depends only on the length of the curve and the radius. A. Gray and L. Vanhecke extended Hotelling's theorem to rank one symmetric spaces computing the volumes of the tubes explicitly in these …

2015-06-08abs ↗pdf ↗

Zoll manifolds with entire Grauert tubes are proven to be standard complex projective spaces.

problem Characterizing Zoll manifolds with entire Grauert tubes.
method Isometric comparison to CPn\mathbb{CP}^n with the canonical metric.
result Zoll manifolds of type CPn\mathbb{CP}^n with entire Grauert tubes are isometric to CPn\mathbb{CP}^n.

Study on volume of tubes and concentration in Riemannian geometry.

problem Understanding concentration loci in Riemannian manifolds and their relation to tube volumes.
method Provided a general formula for tube volumes, specialized to totally geodesic submanifolds, and investigated concentration loci.
result Explicitly proved concentration for codimension one cases and explored characterizations in Wasserstein and Box distances.

A surface is called a tube if its level-sets with respect to some coordinate function (the axis of the surface) are compact. Any tube of zero mean curvature has an invariant, the so-called flow vector. We study how the geometry of the Gaussian image of a higher-dimensional minimal tube M is controlled by the angle alph…

2009-03-02abs ↗pdf ↗

We consider an example of tubes of hypersurfaces in Euclidean space and generalise the tube formula to supercase. By this we assign to a point of the hypersurface in superspace a rational characteristic function. Does this rational function appear when we calculate the zeta-function of an arithmetic variety?

2007-07-13abs ↗pdf ↗

We classify the torsion pairs in a tube category and show that they are in bijection with maximal rigid objects in the extension of the tube category containing the Pruefer and adic modules. We show that the annulus geometric model for the tube category can be extended to the larger category and interpret torsion pairs…

2011-12-28abs ↗pdf ↗

Let M be a real analytic Riemannian manifold. An adapted complex structure on TM is a complex structure on a neighborhood of the zero section such that the leaves of the Riemann foliation are complex submanifolds. This structure is called entire if it may be extended to the whole of TM. We call such manifolds Grauert t…

2017-05-09abs ↗pdf ↗

In this paper, we study the spectrum of quantum tubes. Under certain intrinsic assumptions of the asymptotically flat submanifold of the Euclidean space, we prove the existence of the ground state of the quantum tube. The work is a generalization of Duclos, Exner and Krejcirik (CMP, 223(1), 13-28, 2001) and ourselves(m…

2006-01-10abs ↗pdf ↗

We give a geometric model for a tube category in terms of homotopy classes of oriented arcs in an annulus with marked points on its boundary. In particular, we interpret the dimensions of extension groups of degree 1 between indecomposable objects in terms of negative geometric intersection numbers between correspondin…

2010-11-02abs ↗pdf ↗

To every real analytic Riemannian manifold M there is associated a complex structure on a neighborhood of the zero section in the real tangent bundle of M. This structure can be uniquely specified in several ways, and is referred to as a Grauert tube. We say that a Grauert tube is entire if the complex structure can be…

2000-10-30abs ↗pdf ↗

The study shows that the visible range from a point on harmonic manifolds follows an exponential distribution.

problem Understanding the visible range from a point on harmonic manifolds.
method Analyzing Poisson Boolean models on harmonic manifolds, focusing on the geometric mechanism of tube volumes around geodesic segments.
result The visible range from a point on harmonic manifolds follows an exponential distribution.

The Dirichlet Laplacian in curved tubes of arbitrary cross-section rotating with respect to the Tang frame along infinite curves in Euclidean spaces of arbitrary dimension is investigated. If the reference curve is not straight and its curvatures vanish at infinity, we prove that the essential spectrum as a set coincid…

2004-12-07abs ↗pdf ↗

The paper characterizes D'Atri spaces using total scalar curvature of hemispheres.

problem Characterizing D'Atri spaces using geometric properties.
method Characterization of D'Atri spaces via total scalar curvature of geodesic hemispheres.
result A 3D Riemannian manifold is a D'Atri space if and only if the total scalar curvature of tubes about geodesic segments holds.

The study examines constant mean curvature tubes around geodesics in specific 3-manifolds.

problem Investigating constant mean curvature surfaces in homogeneous 3-manifolds.
method Analyzing horizontal tubes foliating spaces under certain conditions.
result Horizontal tubes foliate spaces under specific curvature conditions.

Researchers prove a complex geometric conjecture about certain manifolds.

problem Compact simply connected Riemannian manifolds with nonnegative sectional curvature.
method Assumption of entire Grauert tube and real analytic structure.
result Compact simply connected Riemannian manifolds with entire Grauert tube are rationally elliptic.