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In this note we discuss the geometry of Riemannian surfaces having a discrete set of singular points. We assume the conformal structure extends through the singularities and the curvature is integrable. Such points are called \emph{simple…

Differential Geometry · Mathematics 2022-01-11 Marc Troyanov

Singularity analysis is essential in robot kinematics, as singular configurations cause loss of control and kinematic indeterminacy. This paper models singularities in bar frameworks as saddle points on constrained manifolds. Given an…

Robotics · Computer Science 2025-10-31 Xuenan Li , Mihnea Leonte , Christian D. Santangelo , Miranda Holmes-Cerfon

Reliable controllers with high flexibility and performance are necessary for the control of intricate, advanced, and expensive systems such as aircraft, marine vessels, automotive vehicles, and satellites. Meanwhile, control allocation has…

Optimization and Control · Mathematics 2016-07-19 David Buzorgnia , Ali Khaki-Sedigh

We suggest a systematic procedure to study D- and F-flat directions in a large class of models with an anomalous U(1). This class of models is characterized by the existence of a vacuum that breaks all Abelian gauge symmetries connecting…

High Energy Physics - Phenomenology · Physics 2009-10-30 Nikolaos Irges , Stéphane Lavignac

When analyzing parametric statistical models, a useful approach consists in modeling geometrically the parameter space. However, even for very simple and commonly used hierarchical models like statistical mixtures or stochastic deep neural…

Machine Learning · Computer Science 2021-12-08 Pascal Mattia Esser , Frank Nielsen

We study the non-selfadjoint Dirac system on the line having an non-integrable regular singularity in an interior point with additional matching conditions at the singular point. Special fundamental systems of solutions are constructed with…

Spectral Theory · Mathematics 2014-10-09 Oleg Gorbunov , Chung-Tsun Shieh , Vjacheslav Yurko

We discuss a new class of coordinate systems for a plane, which provide an analytical representation of arbitrary straightline, and then define the form of potential on the plane, under which the equations of motion of a mass point are…

Dynamical Systems · Mathematics 2007-05-23 Z. Y. Turakulov

In case of a spherically symmetric non-linear scalar field (SF) in flat space, besides singularity at the center, spherical singularities can occur for non-zero values of radial variable $r>0$. We show that in the General Relativity the…

General Relativity and Quantum Cosmology · Physics 2020-04-01 V. I. Zhdanov , O. S. Stashko

We describe an algorithm to construct an intrinsic Delaunay triangulation of a smooth closed submanifold of Euclidean space. Using results established in a companion paper on the stability of Delaunay triangulations on $\delta$-generic…

Computational Geometry · Computer Science 2013-03-27 Jean-Daniel Boissonnat , Ramsay Dyer , Arijit Ghosh

We introduce a new theory of generalised solutions which applies to fully nonlinear PDE systems of any order and allows for merely measurable maps as solutions. This approach bypasses the standard problems arising by the application of…

Analysis of PDEs · Mathematics 2017-02-21 Nikos Katzourakis

This paper considers linear rational expectations models in the frequency domain. The paper characterizes existence and uniqueness of solutions to particular as well as generic systems. The set of all solutions to a given system is shown to…

Econometrics · Economics 2024-11-20 Majid M. Al-Sadoon

Planar central configurations can be seen as critical points of the reduced potential or solutions of a system of equations. By the homogeneity and invariance of the potential with respect to SO(2), it is possible to see that the…

Dynamical Systems · Mathematics 2007-05-23 Davide L. Ferrario

These lectures are designed to provide a general introduction to the Einstein-Vlasov system and to the global Cauchy problem for these equations. To start with some general facts are collected and a local existence theorem for the Cauchy…

General Relativity and Quantum Cosmology · Physics 2007-05-23 Alan D. Rendall

Using invariants from commutative algebra to count geometric objects is a basic idea in singularities. For example, the multiplicity of an ideal is used to count points of intersection of two analytic sets at points of non-transverse…

Algebraic Geometry · Mathematics 2007-05-23 Terence Gaffney

A complete classification of the computational complexity of the fixed-point existence problem for boolean dynamical systems, i.e., finite discrete dynamical systems over the domain {0, 1}, is presented. For function classes F and graph…

Computational Complexity · Computer Science 2008-12-01 Sven Kosub

A smooth map between manifolds is said to be \emph{image simple} if its restriction to its singular point set is a topological embedding. We study the parity of the number of connected components of the singular point set for image simple…

Geometric Topology · Mathematics 2025-10-21 O. Saeki , R. Sadykov

The existence and nature of singularities in locally spatially homogeneous solutions of the Einstein equations coupled to various phenomenological matter models is investigated. It is shown that, under certain reasonable assumptions on the…

General Relativity and Quantum Cosmology · Physics 2015-06-25 Alan D. Rendall

This paper continues the investigation of the formation of naked singularities in the collapse of collisionless matter initiated in [RV]. There the existence of certain classes of non-smooth solutions of the Einstein-Vlasov system was…

General Relativity and Quantum Cosmology · Physics 2018-03-28 Alan D. Rendall , Juan J. L. Velázquez

A symmetric characteristic singular integral equation with two fixed singularities at the endpoints in the class of functions bounded at the ends is analyzed. It reduces to a vector Hilbert problem for a half-disc and then to a vector…

Complex Variables · Mathematics 2015-10-06 Y. A. Antipov

We investigate global properties of the mappings entering the description of symmetries of integrable spin and vertex models, by exploiting their nature of birational transformations of projective spaces. We give an algorithmic analysis of…

High Energy Physics - Theory · Physics 2009-10-22 G. Falqui , C. -M. Viallet