Lower Compact Operators and Applications

Milan Tasković

In this paper we consider a concept of lower compact operators in lower transversal normed spaces. In this sense we obtain the basic statements for lower compact operators. Applications in nonlinear functional analysis are considered. This paper gives sufficient conditions for new solutions of Peano's differential equation in the class of all lower continuous mappings. In this sense, this paper presents new fixed point theorems of Schauder type on lower transversal spaces. For the lower transversal space $(X,\rho)$ are essential the mappings $T: X\to X$ which are unbounded variation, i.e., if $\sum_{n=0}^{\infty} \rho(T^{n}x, T^{n+1}x) = +\infty$ for arbitrary $x\in X$. On the other hand, for upper transversal spaces are essential the mappings $T: X\to X$ which are bounded variation.