Isometries

Luận văn Thạc sĩ Toán học "Bài toán cực tiêu chuẩn nguyên tử của ma trận" nhằm nghiên cứu bài toán cực tiểu chuẩn nguyên tử và các điều kiện giới hạn isometry (RIP) để phương pháp này cho ta nghiệm của bài toán cực tiểu hàm hạng tương ứng. Đồng thời, chúng tôi cũng quan tâm đến các thuật toán tối ưu: phương pháp điểm trong, phương pháp proximal gradient và phiên bản tăng tốc của nó để giải quyết các bài toán cực tiểu chuẩn nguyên tử.

65p mitmit02 18-05-2023 14 5   Download

The goal of this paper is to describe all closed, aspherical Riemannian manifolds M whose universal covers M have a nontrivial amount of symmetry. By this we mean that Isom(M ) is not discrete. By the well-known theorem of Myers-Steenrod [MS], this condition is equivalent to [Isom(M ) : π1 (M )] = ∞. Also note that if any cover of M has a nondiscrete isometry group, then so does its universal cover M . Our description of such M is given in Theorem 1.2 below. The proof of this theorem uses methods from Lie theory, harmonic maps,...

27p dontetvui 17-01-2013 52 7   Download

We prove the Bers density conjecture for singly degenerate Kleinian surface groups without parabolics. 1. Introduction In this paper we address a conjecture of Bers about singly degenerate Kleinian groups. These are discrete subgroups of PSL2 C that exhibit some unusual behavior: • As groups of projective transformations of the Riemann sphere C they act properly discontinuously on a topological disk whose closure is all of C. • As groups of hyperbolic isometries their action on H3 is not convex cocompact. ...

18p noel_noel 17-01-2013 41 5   Download

There are very few examples of Riemannian manifolds with positive sectional curvature known. In fact in dimensions above 24 all known examples are diffeomorphic to locally rank one symmetric spaces. We give a partial explanation of this phenomenon by showing that a positively curved, simply connected, compact manifold (M, g) is up to homotopy given by a rank one symmetric space, provided that its isometry group Iso(M, g) is large. More precisely we prove first that if dim(Iso(M, g)) ≥ 2 dim(M ) − 6, then M is tangentially homotopically equivalent to a rank one symmetric space or M...

63p noel_noel 17-01-2013 55 5   Download

We show that a finitely presented one-ended group which is not commensurable to a surface group splits over a two-ended group if and only if its Cayley graph is separated by a quasi-line. This shows in particular that splittings over two-ended groups are preserved by quasi-isometries. 0. Introduction Stallings in [St1], [St2] shows that a finitely generated group splits over a finite group if and only if its Cayley graph has more than one end.

73p noel_noel 17-01-2013 39 4   Download

Let X = G/K be a homogeneous Riemannian manifold where G is the identity component of its isometry group. A C ∞ function F on X is harmonic if it is annihilated by every element of DG (X), the algebra of all G-invariant differential operators without constant term. One of the most beautiful results in the harmonic analysis of symmetric spaces is the Helgason conjecture, which states that on a Riemannian symmetric space of noncompact type, a function is harmonic if and only if it is the Poisson integral of a hyperfunction over the Furstenberg boundary G/Po where...

59p tuanloccuoi 04-01-2013 53 7   Download

Tuyển tập báo cáo các nghiên cứu khoa học quốc tế ngành hóa học dành cho các bạn yêu hóa học tham khảo đề tài: Research Article Inequalities in Additive N-isometries on Linear N-normed Banach Spaces

12p dauphong18 09-03-2012 34 2   Download