Papers
Book
My book
"Theories,
Sites, Toposes: relating and studying mathematical theories through
topos-theoretic 'bridges'" has recently been published by
Oxford University Press. It can be bought for instance through Amazon or
the OUP website.
Here is the back cover:
This book introduces a set of methods and
techniques for studying mathematical theories and relating them to each
other through the use of Grothendieck toposes. The theory of classifying
toposes – which geometrically embodies the mathematical content of
first-order (geometric) theories - is first recalled, allowing the
formulation of general ‘bridge’ principles: study theories through the
computation of invariants of their associated toposes in terms of
different presentations of these toposes. As any Grothendieck topos has
infinitely many presentations, the expression of its invariants in terms
of them gives rise to a veritable mathematical morphogenesis. These
methods, which are susceptible to unify notions and results across
distinct mathematical areas, are applied in particular to the study of
geometric theories and their extensions through suitable topos-theoretic
invariants. The book concludes with a selection of applications of the
theoretical results obtained in the previous parts to very different
concrete mathematical theories.
Introductory texts
-
This text, which
is a preliminary version of the first two chapters of my book "Theories,
Sites, Toposes: relating and studying mathematical theories through
topos-theoretic 'bridges'", is a self-contained introduction to topos
theory and the 'bridge' technique.
- On 14 December 2016 I successfully defended my
HDR (mémoire
pour l'obtention de l'habilitation à diriger des recherches) at the University
of Paris 7. This document provides an introduction to my research
work and a synthetic description of the contents of my main papers
with an emphasis on their conceptual and methodological aspects; it
presents in particular several selected applications of the 'bridge'
technique in different mathematical fields obtained in the last
years.
The slides of my presentation (in French) are available
here. The
Jury's report ("rapport de soutenance") is available
here.
- Here is another text, written with Laurent Lafforgue in French,
providing an introduction to the theory of toposes as 'bridges'.
This text, which is an expanded version of a recent
talk given by Lafforgue at the Université de Nantes, is
particularly suited for geometers who are not very familiar with
categorical logic and the theory of classifying toposes.
- Here is a
text providing a conceptual introduction to the the theory of
topos-theoretic 'bridges', specifically written for the general
public.
Publications (in reverse chronological order)
- On morphisms of relative toposes (jointly with Léo
Bartoli),
arXiv:math/AG/2310.20691, 46 pages (2023)
- Fibred sites and existential toposes,
arXiv:math/AG/2212.11693, 45 pages (2022)
- Relative topos theory via stacks (jointly with Riccardo
Zanfa),
arXiv:math.AG/2107.04417, 204 pages (2021)
-
The
over-topos at a model
(jointly with Axel Osmond,
arXiv:math.CT/2104.05650, 30 pages (2021)
- La « notion unificatrice » de topos,
38 pages, chapter in the book «
Lectures Grothendieckiennes » (Spartacus IDH and SMF,
2022), available
here
- Grothendieck toposes as unifying ‘bridges’ : a mathematical
morphogenesis, in the
Springer book “Philosophy of Mathematics. Objects,
Structures, and Logics”, available
here
- Denseness conditions, morphisms and equivalences of
toposes,
arXiv:math.CT/1906.08737,
168 pages (2020)
- On the dependent product in toposes (jointly with R.
Zanfa),
arXiv:math.CT/1908.08488,
18 pages (2019), revised version to appear in Mathematical
Logic Quarterly
- Some aspects of topological Galois theory (jointly with
L. Lafforgue), Journal of Geometry and Physics 142,
287-317 (2019).
- Syntactic categories for Nori motives (jointly with L.
Barbieri-Viale and L. Lafforgue), Selecta Mathematica 24(4), 3619-3648
(2018),
preprint version available as
arXiv:math.AG/1506.06113
- On the geometric theory of local MV-algebras (jointly with A. C.
Russo), Journal of Algebra 479, 263-313 (2017),
preprint version available as
arXiv:math.CT/1602.03867
- Cyclic theories (jointly with N. Wentzlaff),
Applied Categorical Structures
25 (1),
105–126 (2017), preprint version
available as arXiv:math.CT/1406.5479
- Lattice-ordered abelian groups and perfect MV-algebras: a
topos-theoretic perspective (jointly with A. C. Russo),
Bulletin of Symbolic Logic 22 (2), 170-214 (2016),
preprint version available as
arXiv:math.CT/1409.4730
- Topological Galois Theory,
Advances in Mathematics 291, 646–695 (2016),
correction note here,
preprint version available as
arxiv:math.CT/1301.0300
-
Sur
la dualité des topos et de leurs présentations et ses applications :
une introduction
(in French,
jointly
with L.
Lafforgue),
available
here
(2016),
61 pages
- Priestley-type dualities for partially
ordered structures, Annals of
Pure and Applied Logic 167 (9), 820-849 (2016), correction
note here, preprint
version available as arXiv:math.CT/1203.2800
- The Morita-equivalence between MV-algebras and abelian
l-groups with strong unit (jointly with A. C. Russo),
Journal of Algebra
422, 752–787 (2015), preprint version available as
arxiv:math.CT/1312.1272
- Motivic toposes,
arXiv:math.AG/1507.06271
(2015), 41 pages
- General affine adjunctions, Nullstellensätze, and dualities
(jointly with V. Marra and L. Spada),
arXiv:math.CT/1412.8692,
revised version currently in press in the Journal of Pure
and Applied Algebra (pp. 1-34).
- Extensions of flat functors and theories of presheaf type,
arxiv:math.CT/1404.4610
(2014), 158 pages, incorporated in the book "Theories, Sites,
Toposes: relating and studying mathematical theories through
topos-theoretic 'bridges'"
- Topologies for intermediate logics, Mathematical
Logic Quarterly 60 (4-5), 335-347 (2014), preprint version
available as
arxiv:math.CT/1205.2547
- Gelfand spectra and Wallman
compactifications, arxiv:math.CT/1204.3244
(2012), 50 pages
- A general method for building reflections,
Applied Categorical
Structures 22 (1), 99–118 (2014), preprint version
available as
arXiv:math.CT/1112.3603
- Site characterizations for geometric
invariants of toposes,
Theory and Applications of Categories Vol. 26,
No. 225, pp 710-728 (2012)
- A topos-theoretic approach to Stone-type dualities,
arXiv:math.CT/1006.3930
(2011), 158 pages
- The unification of Mathematics via Topos Theory,
arXiv:math.CT/1006.3930 (2010), 41 pages
(Russian translation available as arXiv:math.CT/1104.0563
),
to appear in a Springer book of the series “Studies in
Universal Logic” in 2020
-
A characterization theorem for
geometric logic,
Annals of Pure and Applied Logic
162 (4), 318-321 (2011), preprint version available as
arXiv:math.CT/0912.1404
-
Syntactic characterizations of properties of classifying
toposes, Theory and Applications of
Categories Vol. 26, No. 6, pp 176-193 (2012)
- Universal models and definability,
Mathematical Proceedings of the Cambridge Philosophical
Society
152 (2) 279-302 (2012), preprint version available as
arXiv:math.CT/0906.3061
- Lattices of theories,
arXiv:math.CT/0905.0299 (2009), 84 pages,
incorporated in the book "Theories, Sites, Toposes:
relating and studying mathematical theories through topos-theoretic
'bridges'"
- Atomic toposes and countable categoricity,
Applied Categorical Structures
20 (4), 379-391 (2012),
preprint version available as
arXiv:math.CT/0811.3547
-
De Morgan's law and the theory of fields
(jointly with P.T. Johnstone),
Advances in Mathematics 222 (6), 2145-2152 (2009),
preprint version available as arXiv:math.CT/0808.1972
- De Morgan classifying toposes,
Advances in Mathematics 222 (6), 2117-2144 (2009),
preprint version available as
arXiv:math.CT/0808.1519
- Fraïssé's construction from a topos-theoretic perspective,
arXiv:math.CT/0805.2778
(2008), 17 pages, to appear in Logica Universalis
-
Yoneda representations of
flat functors and classifying toposes,
Theory and Applications of Categories,
Vol.
26,
No.
21,
pp.
538-553 (2012)
My Ph.D. thesis is available upon
request.
Previous work
The following papers were written during my undergraduate studies.
fg
-
A solution to
recursive second-order linear equations,
Quaderni del Dipartimento di Matematica dell’Università di Torino
(12/2005), 10 pages
- An
unconventional solution to an Eulerian problem,
Quaderni del Dipartimento di Matematica dell’Università di Torino
(12/2005), 14 pages