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Related papers: Curvature bounds on length-minimizing discs

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We present the results of our studies on accretion disks in the proximity of astrophysical black holes. These disks can be of varying degrees of opacity, geometrical shapes, sizes, and volumes. The central compact object is a Schwarzschild…

High Energy Astrophysical Phenomena · Physics 2023-02-27 Leela Elpida Koutsantoniou

We show how circumradius and asymptotic behavior of curves in CAT(0) and CAT(K) spaces(K>0) are controlled by growth rates of total curvature. We apply our results to pursuit and evasion games of capture type with simple pursuit motion,…

Metric Geometry · Mathematics 2009-09-24 S. Alexander , R. Bishop , R. Ghrist

We establish the existence of hypersurfaces with constant mean curvature and a prescribed boundary in Euclidean space, represented as radial graphs over domains of the unit sphere. Under the assumptions that the mean curvature of the…

Differential Geometry · Mathematics 2025-07-25 Flávio Cruz , José T. Cruz , Jocel Oliveira

We prove a polynomial upper bound on the number of resonances in a disc whose radius tends to infinity for even asymptotically hyperbolic manifolds with real-analytic ends. Our analysis also gives a similar upper bound on the number of…

Analysis of PDEs · Mathematics 2024-11-27 Malo Jézéquel

Although the Eddington limit has originally been derived for stars, recently its relevance for the evolution of accretion discs has been realized. We discuss the question whether the classical Eddington limit - which has been applied…

Astrophysics · Physics 2008-11-26 D. Heinzeller , W. J. Duschl

We construct sense-preserving univalent harmonic mappings which map the unit disk onto a domain which is convex in the horizontal direction, but with varying dilatation. Also, we obtain minimal surfaces associated with such harmonic…

Complex Variables · Mathematics 2015-08-04 YuePing Jiang , ZhiHong Liu , Saminathan Ponnusamy

Standard accretion disc model relies upon several assumptions, the most important of which is geometrical thinness. Whenever this condition is violated, new physical effects become important such as radial energy advection and mass loss…

High Energy Astrophysical Phenomena · Physics 2015-10-28 Pavel Abolmasov , Anna Chashkina

We derive new, sharp lower bounds for certain curvature functionals on the space of Riemannian metrics of a smooth compact 4-manifold with a non-trivial Seiberg-Witten invariant. These allow one, for example, to exactly compute the infimum…

Differential Geometry · Mathematics 2009-10-31 Claude LeBrun

We prove various inequalities measuring how far from an isometry a local map from a manifold of high curvature to a manifold of low curvature must be. We consider the cases of volume-preserving, conformal and quasi-conformal maps. The…

Differential Geometry · Mathematics 2014-03-18 Benoît Kloeckner

In this paper we prove some general results on constant mean curvature lamination limits of certain sequences of compact surfaces $M_n$ embedded in $\mathbb R^3$ with constant mean curvature $H_n$ and fixed finite genus, when the boundaries…

Differential Geometry · Mathematics 2016-05-02 William H. Meeks , Giuseppe Tinaglia

In [5], a rigidity result was obtained for outermost marginally outer trapped surfaces (MOTSs) that do not admit metrics of positive scalar curvature. This allowed one to treat the "borderline case" in the author's work with R. Schoen…

General Relativity and Quantum Cosmology · Physics 2018-03-14 Gregory J. Galloway

In this paper we report on the formation of magnetically-levitating accretion disks around supermassive black holes. The structure of these disks is calculated by numerically modelling tidal disruption of magnetized interstellar gas clouds.…

Astrophysics of Galaxies · Physics 2015-06-03 Evghenii Gaburov , Anders Johansen , Yuri Levin

We study the compactness problem for moduli spaces of holomorphic supercurves which, being motivated by supergeometry, are perturbed such as to allow for transversality. We give an explicit construction of limiting objects for sequences of…

Symplectic Geometry · Mathematics 2015-02-24 Josua Groeger

This article derives lower bounds on the supremal (strict) p-negative type of finite metric spaces using purely elementary techniques. The bounds depend only on the cardinality and the (scaled) diameter of the underlying finite metric…

Functional Analysis · Mathematics 2008-07-18 Anthony Weston

We prove that Riemannian metrics with an absolute Ricci curvature bound and a conjugate radius bound can be smoothed to having a sectional curvature bound. Using this we derive a number of results about structures of manifolds with Ricci…

dg-ga · Mathematics 2008-02-03 Xianzhe Dai , Guofang Wei , Rugang Ye

We present an analogue to the Majorisation Theorem of Reshetnyak in the setting of Lorentzian length spaces with upper curvature bounds: given two future-directed timelike rectifiable curves $\alpha$ and $\beta$ with the same endpoints in a…

Differential Geometry · Mathematics 2026-05-05 Tobias Beran , Felix Rott

We lay the groundwork for a UV-complete formulation of the Euclidean Jackiw-Teitelboim two-dimensional models of quantum gravity when the boundary lengths are finite, emphasizing the discretized approach. The picture that emerges is…

High Energy Physics - Theory · Physics 2024-06-12 Frank Ferrari

In this paper, we study curvature estimates for nodal sets of harmonic functions in the plane. We prove that at any point $p$, the curvature of each nodal curve of any harmonic function $u$ is upper bounded by…

Analysis of PDEs · Mathematics 2024-09-06 Jin Sun

In this paper, we solve the longstanding Gaussian curvature conjecture of a minimal graph $S$ over the unit disk. The conjecture asserts that for any minimal graph above the unit disk, the Gaussian curvature at the point directly above the…

Differential Geometry · Mathematics 2025-06-10 David Kalaj , Petar Melentijevic

We study several geometric and analytic aspects of Dirac-harmonic maps with curvature term from closed Riemannian surfaces.

Differential Geometry · Mathematics 2015-12-01 Volker Branding