The indefinite least-squares problem has been thoroughly studied before under the assumption that the range of C is a uniformly J-positive subspace of K. Along this article the range of C is only supposed to be a J-nonnegative ...

Kerin spaces as a generalization of Hilbert spaces, appear in the same way in different areas of physics where the main difference is the possibility of having an indefinite internal product and gain properties that in the ...

The generalized coherent states of Perelomov of the group pseudo-unitary 2 x 2-matrices with determinant equal to 1, SU(1; 1), have been widely studied for their importance in physics, but always on Hilbert spaces of ...

Along this work we study an indefinite abstract smoothing problem. After establishing necessary and sufficient conditions for the existence of solutions to this problem, the set of admissible parameters is discussed in ...

Muestra la teoría de punto fijo basado en las consideraciones de orden y completitud, resaltando la importancia de los teoremas de Knaster-Tarski y Bishop-Phelps. De igual manera la teoría de triangulación y triangulación ...