activity
20092026
most citedOn the number of type change loci of a generalized complex structure

19 citations · 45 across the 20 of their papers we have counts for

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10 papers · 1 filter

math.GT2026

A novel construction of homotopy 4-spheres and real projective 4-spaces à la Cappell-Shaneson

Rafael Torres

We produce new collections of homotopy 4-spheres and homotopy real projective 4-spaces by extending a classical construction due to Cappell-Shaneson. We use the extension to devise…

math.GT2023

Smooth structures on non-orientable -manifolds via twisting operations

Valentina Bais, Rafael Torres

Four observations compose the main results of this note. The first records the existence of a smoothly embedded 2-sphere inside such that performing…

math.GT2022★ 1 cited

A recipe for exotic 2-links in closed 4-manifolds whose components are topological unknots

Valentina Bais, Younes Benyahia, Oliviero Malech +1

We describe a construction procedure of infinite sets of -links in closed simply connected 4-manifolds that are topologically isotopic, smoothly inequivalent and componentwise t…

math.GT2022★ 1 cited

Topologically isotopic and smoothly inequivalent 2-spheres in simply connected 4-manifolds whose complement has a prescribed fundamental group

Rafael Torres

We describe a procedure to construct infinite sets of pairwise smoothly inequivalent 2-spheres in simply connected 4-manifolds, which are topologically isotopic and whose complemen…

math.GT2020

Smoothly knotted and topologically unknotted nullhomologous surfaces in 4-manifolds

Rafael Torres

We point out that recent constructions of inequivalent smooth structures yield a manufacturing procedure of infinite sets of pairwise smoothly non-isotopic nullhomologous 2-tori an…

math.GT2018

Topology change and selection rules for high-dimensional $\Spin(1, n)_0$-Lorentzian cobordisms

Gleb Smirnov, Rafael Torres

We study necessary and sufficient conditions for the existence of Lorentzian and weak Lorentzian cobordisms between closed smooth manifolds of arbitrary dimension such that the str…

math.GT2014★ 1 cited

Cauchy surfaces and diffeomorphism types of globally hyperbolic spacetimes

Rafael Torres

Chernov-Nemirovski observed that the existence of a globally hyperbolic Lorentzian metric on a (3 + 1)-spacetime pins down a smooth structure on the underlying 4-manifold. In this…

math.GT2013

Smooth structures on non-orientable four-manifolds and free involutions

Rafael Torres

In this paper, we investigate existence of inequivalent smooth structures on closed smooth non-orientable 4-manifolds building upon results of Akbulut, Cappell-Shaneson, Fintushel-…

math.GT2009★ 4 cited

On the geography and botany of irreducible nonspin 4-manifolds with abelian fundamental group

Rafael Torres

The geography and botany of smooth/symplectic nonspin 4-manifolds with abelian fundamental group are addressed.

math.GT2009

Irreducible 4-manifolds with abelian non-cyclic fundamental group of small rank

Rafael Torres

A myriad of irreducible symplectic 4-manifolds with abelian non-cyclic fundamental group is constructed. The botany of manifolds with finite non-cyclic fundamental groups is also s…