We use Heegaard decompositions and the theta divisor on a Riemann-ian surface to define a three-manifold invariant for rational homology three-spheres. This invariant is defined on the set of Spin c structures θ : Spin c (Y) −→ Q. In the first part of the paper, we give the definition of the invariant (which builds on the theory developed in [18]). In the second part, we establish a relationshi...

a heyting algebra is a distributive lattice with implication and a dual $bck$-algebra is an algebraic system having as models logical systems equipped with implication. the aim of this paper is to investigate the relation of heyting algebras between dual $bck$-algebras. we define notions of $i$-invariant and $m$-invariant on dual $bck$-semilattices and prove that a heyting semilattice is equiva...

magnetotelluric (mt) method is an electromagnetic technique that uses the earth natural field to map the electrical resistivity changes in subsurface structures. because of the high penetration depth of the electromagnetic fields in this method (tens of meters to tens of kilometers), the mt data is used to investigate the shallow to deep subsurface geoelectrical structures and their dimensions....

We study representations of compact surface groups on Hermitian symmetric spaces and characterize those with maximal Toledo invariant. To cite this article: M. Burger et al., C. R. Acad. Sci. Paris, Ser. I 336 (2003).  2003 Académie des sciences/Éditions scientifiques et médicales Elsevier SAS. All rights reserved. Résumé Nous étudions les représentations d’un groupe de surface compacte sur un...

A Heyting algebra is a distributive lattice with implication and a dual $BCK$-algebra is an algebraic system having as models logical systems equipped with implication. The aim of this paper is to investigate the relation of Heyting algebras between dual $BCK$-algebras. We define notions of $i$-invariant and $m$-invariant on dual $BCK$-semilattices and prove that a Heyting semilattice is equiva...

The purpose of this note is to explain how to use the equivariant method of moving frames, [1, 10], to derive the differential invariants, invariant differential operators and invariant differential forms for surfaces in three-dimensional Euclidean space. This is, of course, a very classical problem and the results are not new; for the classical moving frame derivation, see, for instance, [2, 3...

Lifting modules and their various generalizations as some main concepts in module theory have been studied and investigated extensively in recent decades. Some authors tried to present some homological aspects of lifting modules and -supplemented modules. In this work, we shall present a homological approach to -supplemented modules via fully invariant submodules. Lifting modules and H-suppleme...

In this paper, we propose a new photometric stereo method for estimating diffuse reflection and surface normal from color images. Using dichromatic reflection model, we introduce surface chromaticity as a matching invariant for photometric stereo, which serves as the foundation of the theory of this paper. An extremely simple and robust reflection components separation method is proposed based ...