Kluwer Academic Publishers 2000 Homological Perturbation Theory – A theory that concerns itself with of a collection of techniques for deriving chain complexes which are both smaller and chain homotopy equivalent to a given chain complex (cf. also Complex (in homological algebra)). It is motivated by the desire to find effective algorithms in homological algebra. The cornerstone of the theory i...

In this paper, we introduce a stationary M∞-fuzzy metric on the set C B(X), where M∞-fuzzy metric can be thought of as the degree of nearness between two fuzzy sets with respect to any positive real number and C B(X) is the class of fuzzy sets with nonempty bounded closed α-cut sets. Under the φ-contraction conditions, we give some common fixed point theorems for self-mappings in the space C B(X).

In this paper we prove the knight move theorem for the chromatic graph cohomologies with rational coefficients introduced by L. HelmeGuizon and Y. Rong. Namely, for a connected graph Γ with n vertices the only non-trivial cohomology groups H(Γ), H(Γ) come in isomorphic pairs: H(Γ) = H(Γ) for i > 0 if Γ is non-bipartite, and for i > 0 if Γ is bipartite. As a corollary, the ranks of the cohomolog...

*Correspondence: [email protected]; [email protected] 3Department of Mathematics, Zanjan Branch, Islamic Azad University, Zanjan, Iran Full list of author information is available at the end of the article Abstract In this paper, some new generalization of Darbo’s fixed point theorem is proved by using a F(ψ ,φ)-contraction in terms of a measure of noncompactness. Our result extends to obtai...