arXiv subjects

Emanuele Dotto

Publications and source records attributed to Emanuele Dotto.

22 records · Page 2Linked to original sources

arXiv2014

Homotopy limits of spaces, connectivity and cofinality

This paper contains two results on how homotopy limits of topological spaces interact with connectivity. The first is a formula for the connectivity of the homotopy limit of diagrams shaped over suitably finite categories, in terms of the connectivity of the spaces in the diagram. The second result shows that the homotopy fiber of the restriction map induced on homotopy limits by a functor of indexing categories is itself a homotopy limit, indexed over a Grothendieck construction.

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arXiv2013

A Dundas-McCarthy theorem for bimodules over exact categories

From a bimodule $M$ over an exact category $C$, we define an exact category $C\ltimes M$ with a projection down to $C$. This construction classifies certain split square zero extensions of exact categories. We show that the trace map induces an equivalence between the relative $K$-theory of $C\ltimes M$ and its relative topological cyclic homology. When applied to the bimodule $\hom(-,-\otimes_AM)$ on the category of finitely generated projective modules over a ring $A$ one recovers the classical Dundas-McCarthy theorem for split square zero extensions of rings.

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arXiv2012

Stable real K-theory and real topological Hochschild homology

The classical trace map is a highly non-trivial map from algebraic K-theory to topological Hochschild homology (or topological cyclic homology) introduced by Bökstedt, Hsiang and Madsen. It led to many computations of algebraic K-theory of rings. Hesselholt and Madsen recently introduced a Z/2-equivariant version of Waldhausen S-construction for categories with duality. The output is a certain spectrum with involution, called the real K-theory spectrum KR, and associated bigraded groups analogous to Atiyah's real (topological) K-groups. This thesis develops a theory of topological Hochschild homology for categories with duality, and a Z/2-equivariant trace map from real K-theory to it. The main result of the thesis is that stable KR of the category of projective modules over a split square zero extension of a ring is equivalent to the real topological Hochschild homology of the ring with appropriate coefficients. This is the real version a theorem of Dundas-McCarthy for ordinary K-theory.

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arXiv2012

A relative h-principle via cobordism-like categories

We prove an h-principle with boundary condition for a certain class of topological spaces valued sheaves. The techniques used in the proof come from the study of the homotopy type of the cobordism categories, and they are of simplicial and categorical nature. Applying the main result of this paper to a certain sheaf we find another proof of the Madsen-Weiss theorem, that describes the homotopy type of the classifying space of the cobordism category as the loop space of the Thom space of the complement of the tautological bundle over the Grassmannians.

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