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Based on the joint bidiagonalization process of a large matrix pair $\{A,L\}$, we propose and develop an iterative regularization algorithm for the large scale linear discrete ill-posed problems in general-form regularization: $\min\|Lx\| \…

Numerical Analysis · Mathematics 2020-07-21 Zhongxiao Jia , Yanfei Yang

We study a sequence of connections which is associated with a Riemannian metric and an almost symplectic structure on a manifold. We prove that if this sequence is trivial (i.e. constant) or 2-periodic, then the manifold has a canonical…

Differential Geometry · Mathematics 2007-05-23 Mikhail Shubin

We give conditions on the Lee vector field of an almost Hermitian manifold such that any holomorphic map from this manifold into a (1,2)-symplectic manifold must satisfy the fourth-order condition of being biharmonic, hence generalizing the…

Differential Geometry · Mathematics 2012-04-11 M. Benyounes , E. Loubeau , R. Slobodeanu

We give integral formulas to approximate solutions of Dirichlet and Neumann problems for Helmholtz equation at high frequencies. These approximations are valid in the complementary of a union of convex compact obstacles. The first step of…

Analysis of PDEs · Mathematics 2014-02-18 François Cuvelier

In this paper we regularize the Kepler problem on $\kappa$-spacetime in several different ways. First, we perform a Moser-type regularization and then we proceed for the Ligon-Schaaf regularization to our problem. In particular,…

Mathematical Physics · Physics 2016-11-23 Partha Guha , E. Harikumar , Zuhair N. S

Generalized polyhedral convex optimization problems in locally convex Hausdorff topological vector spaces are studied systematically in this paper. We establish solution existence theorems, necessary and sufficient optimality conditions,…

Optimization and Control · Mathematics 2017-10-02 Nguyen Ngoc Luan , Jen-Chih Yao

Variational regularisation is the primary method for solving inverse problems, and recently there has been considerable work leveraging deeply learned regularisation for enhanced performance. However, few results exist addressing the…

Optimization and Control · Mathematics 2024-06-18 Zakhar Shumaylov , Jeremy Budd , Subhadip Mukherjee , Carola-Bibiane Schönlieb

We derive the Holstein-Primakoff oscillator realization on the coadjoint orbits of the $SU(N+1)$ and $SU(1,N)$ group by treating the coadjoint orbits as a constrained system and performing the symplectic reduction. By using the action-angle…

High Energy Physics - Theory · Physics 2009-10-30 Phillial Oh , Chaiho Rim

In this paper, we extend two celebrated inequalities by Busemann -- the random simplex inequality and the intersection inequality -- to both complex and quaternionic vector spaces. Our proof leverages a monotonicity property under…

Metric Geometry · Mathematics 2024-09-24 Christos Saroglou , Thomas Wannerer

In this article, we study the regularity of minimizing and stationary $p$-harmonic maps between Riemannian manifolds. The aim is obtaining Minkowski-type volume estimates on the singular set $S(f)=\{x \ \ s.t. \ \ f \text{ is not continuous…

Analysis of PDEs · Mathematics 2016-10-31 Aaron Naber , Daniele Valtorta , Giona Veronelli

We derive a uniform approximation for semiclassical contributions of periodic orbits to the spectral density which is valid for generic period-quadrupling bifurcations in systems with a mixed phase space. These bifurcations involve three…

chao-dyn · Physics 2008-02-03 Martin Sieber , Henning Schomerus

The main aim of this survey paper is to gather together some results concerning the Calabi type duality discovered by Hojoo Lee between certain families of (spacelike) graphs with constant mean curvature in Riemannian and Lorentzian…

Differential Geometry · Mathematics 2018-03-20 José M. Manzano

To study asymptotic structures, we regularize Einstein's field equations by means of conformal transformations. The conformal factor is chosen so that it carries a dimensional scale that captures crucial asymptotic features. By choosing a…

General Relativity and Quantum Cosmology · Physics 2009-11-11 Niklas Rohr , Claes Uggla

We deal with the reduced four-equation model for the dynamics of heterogeneous compressible binary mixtures with the stiffened gas equations of state. We study its further reduced form, with the excluded volume concentrations, and with a…

Numerical Analysis · Mathematics 2025-12-30 A. Zlotnik , T. Lomonosov

We review a recent proposal for the regularization of the scalar constraint of General Relativity in the context of LQG. The resulting constraint presents strengths and weaknesses compared to Thiemann's prescription. The main improvement is…

General Relativity and Quantum Cosmology · Physics 2015-05-30 Emanuele Alesci

The paper studies the quantum action for the five-dimensional real $\phi^3$-theory in the case of a general formulation using the background field method. The three-loop renormalization is performed with the usage of a cutoff regularization…

High Energy Physics - Theory · Physics 2024-10-29 A. V. Ivanov , N. V. Kharuk

We consider a discrete model of euclidean quantum gravity in four dimensions based on a summation over random simplicial manifolds. The action used is the Einstein-Hilbert action plus an $R^2$-term. The phase diagram as a function of the…

High Energy Physics - Theory · Physics 2009-10-22 J. Ambjorn , J. Jurkiewicz , C. F. Kristjansen

We study the dependence of geometric quantization of the standard symplectic torus on the choice of invariant polarization. Real and mixed polarizations are interpreted as degenerate complex structures. Using a weak version of the equations…

Symplectic Geometry · Mathematics 2010-01-26 Thomas Baier , José M. Mourão , João P. Nunes

Motived by the heat flow and bubble analysis of biharmonic mappings, we study further regularity issues of the fourth order Lamm-Riviere system $$\Delta^{2}u=\Delta(V\cdot\nabla u)+{\rm div}(w\nabla u)+(\nabla\omega+F)\cdot\nabla u+f$$ in…

Analysis of PDEs · Mathematics 2021-06-10 Chang-Yu Guo , Chang-Lin Xiang , Gao-Feng Zheng

In this work, we study the motions in the region around the equilateral Lagrangian equilibrium points L4 and L5, in the framework of the Circular Planar Restricted Three-Body Problem (hereafter, CPRTBP). We design a semi-analytic approach…

Earth and Planetary Astrophysics · Physics 2015-08-04 Rocio Isabel Paez , Ugo Locatelli