PD Dr. Fritz Hörmann

Mathematisches Institut
Albert-Ludwigs-Universität Freiburg

Mitglied im Graduiertenkolleg/Member of the Graduiertenkolleg Cohomological Methods in Geometry


Anschrift/Mail address:Mathematisches Institut
Albert-Ludwigs-Universität Freiburg
Ernst-Zermelo-Strasse 1
D-79104 Freiburg
eMail: fritz.hoermann@math.uni-freiburg.de

Bis September 2019 in Elternzeit und Gast an der/Until September 2019 on paternity leave and guest at the
Université du Luxembourg


Shimura varieties and their compactifications and integral models, arithmetic of quadratic forms, Weil representation, Borcherds' theory, Kudla's conjectures on arithmetic theta functions

Fibered (multi-)derivators, (co)homological descent, Grothendieck's six-functor-formalism, algebraic stacks

Rendering of fractal images: Retinamandelbrot


1 (2005)Komplexe Multiplikation,
Diploma thesis, University of Heidelberg (in German)
98 pages
2 (2010)The arithmetic volume of Shimura varieties of orthogonal type,
Ph.D. thesis, Humboldt-University of Berlin
313 pages
3 (2012)On recursive properties of certain p-adic Whittaker functions,
Journal of Number Theory 132 (2012) pp. 1438-1482
44 pages
4 (2014)The arithmetic and geometric volume of Shimura varieties of orthogonal type,
CRM Monograph Series, Vol 35, Am. Math. Soc.
151 pages
5 (2015)Fibered multiderivators and (co)homological descent,
Theory Appl. Categ., Vol. 32, 2017, No. 38, pp 1258-1362.
105 pages
6 (2016)Six Functor Formalisms and Fibered Multiderivators,
Selecta Mathematica, 24(4), pp. 2841-2925 (2018)
85 pages
7 (2016)Descent for coherent sheaves along formal/open coverings,
submitted for publication
19 pages
8 (2017)Derivator six-functor-formalisms, Definition and Construction I,
submitted for publication
55 pages
9 (2017)Derivator Six-Functor-Formalisms, habilitation thesis
(consists mainly of publications 5, 6 and 9 with an extended introduction)
231 pages
10 (2017)Enlargement of (fibered) derivators,
to appear in J. Pure Applied Algebra
22 pages
11 (2018)(j.w. M. Wendt) Derivators and Tilting,
Appendix to W. Soergel, R. Virk, M. Wendt; Equivariant motives and geometric representation theory, preprint
8 pages
12 (2019)Derivator Six-Functor-Formalisms, Construction II,
87 pages
13 (2019)Generalized automorphic sheaves and the proportionality principle of Hirzebruch-Mumford (revised version),
submitted for publication
35 pages
14 Derivator Six-Functor-Formalisms, Extension to stacks,
work in progress


Workshop on Derivators
April 9-12, 2019
University of Regensburg

Past events:
Summer school Derivators, Freiburg 18.8-22.8.2014
Workshop on "Homotopical approaches to categories and geometry", Freiburg June 2-3, 2016
Workshop on Derivators, Prague, Czech Republic, December 12-16, 2016
Summer school "Degeneration of Calabi-Yau varieties and arithmetic", Freiburg, October 9-13, 2017

Lehrveranstaltungen vergangener Semester

Fall 2010 (McGill)Math 316 - Complex analysis
Winter 2011 (McGill)Math 571 - Higher Algebra 2
Sommer 2011 (Freiburg)Assistent Vorlesung Diskrete Algebraische Strukturen
Winter 2011/12 (Freiburg)Assistent Vorlesung Algebraische Zahlentheorie
Winter 2011/12 (Freiburg)Proseminar Elementare Zahlentheorie
Winter 2011/12 (Freiburg)Seminar on Mordell's conjecture
Sommer 2012 (Freiburg)Projektseminar Algebraische Zahlentheorie - Analysis auf Adel- und Idelgruppen
Sommer 2012 (Freiburg)Assistent Vorlesung Mathematik II für Informatiker
Sommer 2012 (Freiburg)Organisation SWAS
Winter 2012/13 (Regensburg)Lectures on Shimura varieties
Sommer 2013 (Freiburg)Proseminar Graphentheorie
Sommer 2013 (Freiburg)Assistent Vorlesung Kommutative Algebra
Winter 2013/14 (Freiburg)Seminar Algebraische Geometrie (mit Dr. M. Wendt)
Winter 2013/14 (Freiburg)Assistent Vorlesung Algebra und Zahlentheorie
Sommer 2014 (Freiburg)Vorlesung Kommutative Algebra und Einführung in die algebraische Geometrie
Winter 2014/15 (Freiburg)Seminar: Endliche Algebraische Gruppen
Winter 2014/15 (Freiburg)Assistent Vorlesung Mathematik I für Ingenieure und Informatiker
Sommer 2015 (Freiburg)Assistent Vorlesung Mathematik II für Informatiker
Winter 2015/16 (Freiburg)Lectures on Shimura varieties
Sommer 2016 (Freiburg)Vorlesung Algebraische Zahlentheorie
Sommer 2016 (Freiburg)GRK Seminar on "Codimension 2"
Winter 2016/17 (Freiburg)Seminar Klassenkörpertheorie
Sommer 2017 (Freiburg)Seminar zur Algebra
Winter 2017/18 (Freiburg)Assistent Vorlesung Mathe I für Informatiker und Ingeniuere
Sommer 2018 (Freiburg)Vorlesung Algebraische Zahlentheorie
Winter 2018/19 (Freiburg)Seminar Adele (mit Prof.Huber-Klawitter)
Winter 2018/19 (Freiburg)Assistent Vorlesung Lineare Algebra I

Scripts and Documents

The following are lecture notes and some writings not intended for publication. They are not always carefully proofread and sometimes preliminary.

2008Compactifications of moduli spaces and mixed Hodge structures - with applications to automorphic forms
2010The arithmetic volumes of Shimura varieties of orthogonal type
Projector slides
2011Toroidal compactifications of Hilbert modular varieties
Projector slides
2011Divisorial rings and Cox rings
2014Homotopy limits and colimits in nature - A motivation for derivators
Notes for the summer school on derivators
2014Kommutative Algebra und Einführung in die algebraische Geometrie
Vorlesungsskript (in German)
2015The Weil representation and Eisenstein series
2016The Tate and Weil conjetures for rational K3 surfaces
2016Lectures on Shimura varieties
Lecture notes
2018Algebraische Zahlentheorie
Vorlesungsskript (in German)
2018The Birch and Swinnerton-Dyer conjecture
Animated and interactive projector slides programmed in C/GLSL
2019The ∞-categorical interpretation of Abelian and non-Abelian derived functors
Preliminary notes.


Familie/Family: Antonella Perucca

beamermath Animated and interactive projector slides programmed in C/GLSL

Graduiertenkolleg Cohomological Methods in Geometry

Süd-West-Arithmetik-Seminar (SWAS)

Arbeitsgruppe Zahlentheorie Freiburg/Workgroup Number Theory Freiburg

The Québec-Vermont Number Theory Seminar

First Montreal-Toronto Workshop in Number Theory

Second Montreal-Toronto Workshop in Number Theory