An explicit Riemannian metric with Euclidean signature and anti-self dual curvature that does not admit any Killing vectors is presented. It could be a class of metrics on K3, or on surfaces whose universal covering is K3. This metric contains an infinite number of arbitrary parameters, so further work is required to identify the finite number of essential parameters characterizing K3. PACS num...

An explicit Riemannian metric with Euclidean signature and anti-self dual curvature that does not admit any Killing vectors is presented. It could be a class of metrics on K3, or on surfaces whose universal covering is K3. This metric contains an infinite number of arbitrary parameters, so further work is required to identify the finite number of essential parameters characterizing K3. PACS num...

This paper proposes a new approach to the analysis of the steady-state performance of constant modulus algorithms (CMA), which are among the most popular adaptive schemes for blind equalization. A major feature of the proposed feedback approach is that it bypasses the need for working directly with the weight error covariance matrix. In so doing, approximate expressions for the steady-state mea...

The antecedent of Einstein field equations with Euclidean signature is the complex elliptic Monge-Ampère equation, CMA2. For elliptic CMA2 solutions determine hyper-Kähler, self-dual and therefore Ricci-flat metrics with Euclidean signature. We shall consider a symmetry reduction of CMA2 to solutions that admit only a single Killing vector. Systematic studies of vacuum metrics with one Killing ...

The antecedent of Einstein field equations with Euclidean signature is the complex elliptic Monge-Ampère equation, CMA2. For elliptic CMA2 solutions determine hyper-Kähler, self-dual and therefore Ricci-flat metrics with Euclidean signature. We shall consider a symmetry reduction of CMA2 to solutions that admit only a single Killing vector. Systematic studies of vacuum metrics with one Killing ...

This paper studies the behavior of the error sequence of stop-and-go variants of two adaptive blind equalizers, namely CMA2-2 and Sato’s algorithm. It is shown that for transmitted signals with constant modulus , the equalizer output can be made to lie within the circle of radius p c infinitely often, for some value of c that is only slightly larger than one.

A convertible authenticated encryption (CAE) scheme is a better way to simultaneously provide cryptographic schemes with the properties of confidentiality, authenticity and non-repudiation. The authors propose a RSA based secure CAE scheme which is different from previously proposed ones based on the discrete logarithms or elliptic curve discrete logarithms. The proposed scheme has the nice arb...