5 papers
On the detection of knotted spheres by their traces in high dimensions
Valentina Bais, Alessio Di Prisa, Daniel Hartman +8
For every , we demonstrate the existence of non-isotopic smooth -knots in with diffeomorphic traces by generalising the RBG link construction to all dimensio…
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…
-structures on non-oriented 4-manifolds via Lefschetz fibrations
Valentina Bais
We study necessary and sufficient conditions for a 4-dimensional Lefschetz fibration over the 2-disk to admit a -structure, extending the work of A. Stipsicz in t…
On Dold-Whitney's parallelizability of 4-manifolds
Valentina Bais
We present a proof of the fact that a closed orientable 4-manifold is parallelizable if and only if its second Stiefel-Whitney class, first Pontryagin class and Euler characteristi…
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…