An important aspect of data modeling is the identification of entities or objects and their associated attributes. An attribute may be single-valued or multivalued. During database design, the designer usually has to represent all attributes in relational tables that only allow single-valued cells. A number of authors (1, 3, 5, 6) advocate the notion that multivalued attributes are essentially ...

In this paper,  we introduce the notion of  generalized multivalued  $F$- weak contraction and we prove some fixed point theorems related to introduced  contraction for multivalued mapping in complete metric spaces.  Our results extend and improve the results announced by many others with less hypothesis. Also, we give some illustrative examples.

More work is needed on devising practical, but theoretically wellfounded procedures for doing object-oriented database (OODB) &sign. Besides being practical and having formal properties, these design procedures should alSo be flexible enough to allow for peculiarities that make applications unique. In this paper. we present and discuss an OODB design procedure that addresses these problems. The...

on a finsler manifold, we define conformal vector fields and their complete lifts and prove that incertain conditions they are homothetic.

We quantize the Maxwell Chern Simons theory in a geometric representation that generalizes the Abelian Loop Representation of Maxwell theory. We find that in the physical sector, the model can be seen as the theory of a massles scalar field with a topological interaction that enforces the wave functional to be multivalued. This feature allows to relate the Maxwell Chern Simons theory with the q...

In this paper, we explain a new generalized contractive condition for multivalued mappings and prove a fixed point theorem in metric spaces (not necessary complete) which extends some well-known results in the literature. Finally, as an application, we prove that a multivalued function satisfying a general linear functional inclusion admits a unique selection fulfilling the corresp...

Liouville and Toda gravity theories with non-vanishing interaction potentials have spectra obtained by dividing the free-field spectra for these cases by the Weyl group of the corresponding A 1 or A 2 Lie algebra. We study the canonical transformations between interacting and free fields using the technique of intertwining operators, giving explicit constructions for the wavefunctions and showi...

In this paper a class of conformal field theories with nonabelian and discrete group of symmetry is investigated. These theories are realized in terms of free scalar fields starting from the simple b− c systems and scalar fields on algebraic curves. The KnizhnikZamolodchikov equations for the conformal blocks can be explicitly solved. Besides of the fact that one obtains in this way an entire c...