We prove that for n ≥ 1 and q > 0 the (oriented) cobordism group of fold maps of (oriented) (n + q)-dimensional manifolds into R contains the direct sum of ⌊(q + 1)/2⌋ copies of the (n − 1)th stable homotopy group of spheres as a direct summand. We also prove that for k ≥ 1 and q = 2k − 1 the cobordism group of fold maps of unoriented (n+ q)-dimensional manifolds into R also contains the nth st...

We define holomorphic connection on a parabolic vector bundle over a Riemann surface and prove that a parabolic vector bundle admits a holomorphic connection if and only if each direct summand of it is of parabolic degree zero. This is a generalization to the parabolic context of a well-known result of Weil which says that a holomorphic vector bundle on a Riemann surface admits a holomorphic co...

Let X be a complex K3 surface, $$\textrm{Diff}(X)$$ the group of diffeomorphisms and $$\textrm{Diff}_0(X)$$ identity component. We prove that fundamental contains free abelian countably infinite rank as direct summand. The summand is detected using families Seiberg–Witten invariants. moduli space Einstein metrics on used key ingredient in proof.

We give an example of a direct summand of a serial module that does not admit an indecomposable decomposition.

The aim of this paper is to investigate strong notion strongly ⨁-supplemented modules in module theory, namely ⨁-locally artinian supplemented modules. We call a M if it locally and its supplement submodules are direct summand. In study, we provide the basic properties particular, show that every summand supplemented. Moreover, prove ring R semiperfect with radical only projective R-module