in this paper, we study the chebyshev centres of bounded subsets of normed spaces and obtain a norm inequality for relative centres. in particular, we prove that if t is a remotal subset of an inner product space h, and f is a star-shaped set at a relative chebyshev centre c of t with respect to f, then llx - qt (x)1i2 2 ilx-cll2 + ilc-qt (c) 112 x e f, where qt : f + t is any choice function s...

We present an introduction to Hilbert space frames. A frame is a generalization of a basis that is useful, for example, in signal processing. It allows us to expand Hilbert space vectors in terms of a set of other vectors that satisfy a certain “energy equivalence” condition. This condition guarantees that any vector in the Hilbert space can be reconstructed in a numerically stable way from its...

We describe a construction of fibrewise inner products on the cotangent bundle of the smooth free loop space of a Riemannian manifold. Using this inner product, we construct an operator over the loop space of a string manifold which is directly analogous to the Dirac operator of a spin

In this paper, we propose a definition for semi-inner product in the space of p-summable sequences equipped with an n-norm. Using definition, introduce concepts pn-orthogonality and pn-angle between two vectors sequences. For special case n = 1, these are identical to previous studies. We also notion one-dimensional subspaces arbitrary-dimensional subspaces. The authors believe that results obt...

The paper the title refers to is that in Proceedings of the Edinburgh Mathematical Society, 40 (1997), 367-374. Taking it as an excuse we intend to realize a twofold purpose: 1o to atomize that important result showing by the way connections which are out of favour, 2o to rectify a tiny piece of history. The objective 1o is going to be achieved by adopting means adequate to goals; it is of grea...

In this paper we will study some aspects of dS/CFT correspondence. We will focus on the relation between Witten's non-standard de Sitter inner product and correlators in the holographic dual conformal field theory. We will argue that from the definition of Witten's inner product and conjecture that the Hilbert space of initial states of massive scalar field on I − in de Sitter space corresponds...

We investigate frame theory over the binary field Z2, following work of Bodmann, Le, Reza, Tobi and Tomforde. We consider general finite dimensional vector spaces V over Z2 equipped with an (indefinite) inner product (·, ·)V which can be an arbitrary bilinear functional. We characterize precisely when two such spaces (V, (·, ·)V ) and (W, (·, ·)W ) are unitarily equivalent in the sense that the...

An Ad K invariant inner product on the Lie algebra of a compact connected Lie group K extends to a Hermitian inner product on the Lie algebra of the complexified Lie group Kc. The Laplace-Beltrami operator, ∆, on Kc induced by the Hermitian inner product determines, for each number a > 0, a Green’s function ra by means of the identity (a2−∆/4)−1 = ra∗. The Hilbert space of holomorphic functions...

In this paper we will study some aspects of dS/CFT correspondence. We will focus on the relation between Witten's non-standard de Sitter inner product and correlators in the holographic dual conformal field theory. We will argue that from the definition of Witten's inner product and conjecture that the Hilbert space of initial states of massive scalar field on I − in de Sitter space corresponds...