5 papers
Smooth structures on definite four-manifolds with infinite fundamental group
Sebastián M. Camponovo, Rafael Torres
For each odd integer , we construct infinitely many pairwise non-diffeomorphic irreducible smooth structures on a definite 4-manifold with infinite fundamental group whose a…
A cut-and-paste mechanism to introduce fundamental group and construct new four-manifolds
Valentina Bais, Rafael Torres
We introduce a simple cut-and-paste mechanism to construct both orientable and nonorientable four-manifolds from a given initial one. This mechanism alters the fundamental group wh…
An observation on the existence of stable generalized complex structures on ruled surfaces
Rafael Torres
We point out that any stable generalized complex structure on a sphere bundle over a closed surface of genus at least two must be of constant type.
Some examples of small irreducible exotic 4-manifolds with free abelian fundamental group
Valentina Bais, Rafael Torres, Daniele Zuddas
We produce examples of pairwise non-diffeomorphic closed irreducible 4-manifolds with non-trivial free abelian fundamental group of rank less than three and small Euler characteris…
Existence results of Spin-pseudo-Riemannian cobordisms
Valentina Bais, Victor Gustavo May Custodio, Rafael Torres
In this note, we study necessary and sufficient conditions for the existence of a Spin -dimensional cobordism that supports a non-singular and non-degenerate pseudo-Rieman…