Moduli of Quiver Representations and GIT Quotients
2025-02-13 14:00 - 16:30 (Europe/Berlin) | Frankfurt, Rober-Mayer-Str. 10, Raum 711 klein
14:00 – 15:00 Talk 7.1: Rızacan Çiloğlu (TU Darmstadt): Nakajima Quiver Varieties
Coffee break
15:30 – 16:30 Talk 7.2: Martin Möller (Goethe Universität): Reincarnations of Quiver Moduli

Workshop "Derived special cycles and Kudla's modularity conjecture"
2025-02-17 - 2025-02-19 | Darmstadt

Ruth Moufang Lectures 2025 (2nd lecture)
2025-03-14 10:00 - 13:00 | Mainz, Hilbertraum (05-432)
Kirsten Wickelgren (Duke University) – Seminar talks
“Gromov–Witten invariants in A1-homotopy theory” (10:30 – 11:30)
“A1-homotopy theory and the Weil Conjectures” (12:00 – 13:00)

Workshop "Graduate Research Opportunities for Women (GROW) 2025"
2025-03-27 - 2025-03-28 | Frankfurt, Hilbertraum, Rober-Mayer-Str. 6-8, Raum 302

Workshop "Combinatorial Algebraic Geometry: Highlighting Underrepresented Genders"
2025-03-31 - 2025-04-04 | Frankfurt am Main

Junior Retreat
2025-04-07 - 2025-04-10 | Jugendherberge Limburg

Motivic Spectra
2025-04-14 10:15 - 11:45 | Mainz, Hilbertraum (05-432) and Zoom
Talk 1: Definition of motivic spectra (Andreas Gieringer)
Define elementary and smooth blowup excision [AHI25, Definition 2.1], and prove that Nisnevich-locally they agree [AHI25, Proposition 2.2]. Explain how to invert and object c in a presentable symmetric monoidal ∞-category C, i.e. explain [AI22, Proposition 1.3.14].
Note that in general, this is not given by the c-telescope colimPrL(C−⊗c −−→ C → . . . ). End the talk by giving the definition of MSS, as in the beginning of [AHI25, Section 4]. If time permits, explain the basic functoriality of MSS.

Categorical Deligne–Langlands correspondence
2025-04-22 14:00 - 15:30 | Darmstadt, Room 401 and Zoom, Schlossgartenstraße 7, Darmstadt, 64289, Germany
Yanik Kleibrink (TU Darmstadt): Talk 1* – Weil–Deligne representations
Zoom (612 2072 7363, Password: [REDACTED] six digit prime number)

Locally analytic vector bundles on the Fargues-Fontaine-Curve
2025-04-24 11:15 - 13:15 | Heidelberg, Mathematikon, SR 8 and Zoom, INF 205, Heidelberg, Germany
The adic Fargue-Fontaine curve
speaker: Max Witzelsperger (Heidelberg)

Berkovich motives
2025-04-24 13:00 - 13:30 | Darmstadt, Room 315 and Zoom, Schlossgartenstraße 7, Darmstadt, 64289, Germany
Talk 0: Overview (15min) ( Alberto Merici)

Berkovich motives
2025-04-24 13:30 - 15:00 | Darmstadt, Room 315 and Zoom, Schlossgartenstraße 7, Darmstadt, 64289, Germany
Talk 1: Motives (Christian Dahlhausen)

Holomorphic triple products
2025-04-24 14:00 - 16:00 | Mainz, Hilbertraum (05-432)
Jonas Stelzig (LMU München / JGU Mainz)
Abstract: I will introduce, and survey the context of, ABC triple Massey products, a holomorphic analogue of ordinary triple Massey products for complex manifolds. Then, I will discuss the (non)vanishing of these operations in situations of geometric interest, including toric, compact homogeneous Kähler, and Calabi Yau manifolds.

Berkovich motives
2025-04-24 15:30 - 16:30 | Darmstadt, Room 315 and Zoom, Schlossgartenstraße 7, Darmstadt, 64289, Germany
Talk 2: Cancellation Theorem (75min) ( Alberto Merici)

D-elliptic sheaves and the Hasse principle
2025-04-25 09:00 - 11:00 | Heidelberg, Mathematikon, SR 8 and Zoom, INF 205, Heidelberg, Germany
Overview
Sriram Chinthalagiri Venkata (Heidelberg)
Begin by recalling Drinfeld’s theory of elliptic sheaves (or Shtukas) ([Mumford; Dri87]), andexplain briefly the importance of considering generalizations of them equipped with an action of D, namely D-elliptic sheaves. Then motivate and explain the main result in [Ara+24], by summarizing each talk of the seminar.

From p-adic Hodge theory to motivic cohomology and back
2025-04-25 13:30 - 14:30 | Heidelberg, Mathematikon, SR A and Livestream
Tess Bouis (Universität Regensburg)
Abstract: The initial goal of p-adic Hodge theory, as formulated by the foundational conjectures of Fontaine in the 1980s, is to compare the different p-adic cohomology theories one can associate to schemes of mixed characteristic (0,p). If Fontaine’s conjectures have now been solved by the work of many people, the recent development of prismatic cohomology has shed new light on integral aspects of this theory. In this talk, I want to explain how one can use these recent advances in p-adic Hodge theory to construct a new theory of motivic cohomology for general (qcqs) schemes. This theory generalises the recent construction of Elmanto-Morrow over a field to mixed characteristic, and allows us to give a simplified motivic approach to certain classical results in p-adic Hodge theory. This is part of a joint work in progress with Arnab Kundu.

Seminar on Arithmetic Geometry
2025-04-25 15:30 - 17:00 | Darmstadt, Room 401 and Zoom, Schlossgartenstraße 7, Darmstadt, 64289, Germany
Zhixiang Wu (Universität Münster): Bernstein-Zelevinsky duality for locally analytic principal series representations
Bernstein-Zelevinsky duality is classically a duality on the derived category of smooth representations of a p-adic Lie group. In this talk, we will consider the Bernstein-Zelevinsky duality for locally analytic representations of p-adic Lie groups, and compute explicitly the duality for principal series representations. I will also explain the relationship of this duality with the duality of coherent sheaves on the (patched) eigenvariety. This is joint work with Matthias Strauch.
Zoom (635 7328 0984, Kenncode: kleinste sechsstellige Primzahl

Motivic Spectra
2025-04-28 10:15 - 11:45 | Mainz, Hilbertraum (05-432) and Zoom
Talk 2: Thom-spaces (Timo Weiß)

Categorical Deligne–Langlands correspondence
2025-04-29 14:00 - 15:30 | Darmstadt, Room 401 and Zoom, Schlossgartenstraße 7, Darmstadt, 64289, Germany
Talk 2: Michelle Klemt: Spaces of L-parameters
Zoom (612 2072 7363, Password: [REDACTED] six digit prime number)

Algebraic proof of modular form inequalities for optimal sphere packings
2025-04-29 16:00 - 17:00 | Zoom
International Seminar on Automorphic Forms
Seewoo Lee (UC Berkeley)
https://tu-darmstadt.zoom.us/j/68048280736
The password is the first Fourier coefficient of the modular j-function (as digits)

Gromov-Witten theory and real enumerative geometry
2025-04-30 14:15 - 17:00 | Frankfurt, Robert-Mayer-Str. 6-8, Raum 309
14:15 – 15:15 Talk 1: Andrei Bud (Universität Frankfurt): Real structures in low genus
15:45 – 16:45 Talk 2: Jeonghoon So (Universität Frankfurt): Counting coverings

D-elliptic sheaves and the Hasse principle
2025-05-02 09:00 - 11:00 | Heidelberg, Mathematikon, SR 8 and Zoom, INF 205, Heidelberg, Germany
Stacks I
speaker: Chia-Fu Yu (Academia Sinica, Taiwan)

Seminar on Arithmetic Geometry
2025-05-02 15:30 - 17:00 | Darmstadt, Room 401 and Zoom, Schlossgartenstraße 7, Darmstadt, 64289, Germany
Christian Dahlhausen (Universität Heidelberg): Duality in (perfect) motivic homotopy theory
This talk treats a conjectured duality on modules over
K-theory in the stable homotopy category of a scheme whose dualising
object is given by G-theory. I shall explain a proof of the conjecture
for quasi-excellent schemes in characteristic zero. In order to approach
the conjecture in positive characteristic, I sketch the construction of
a “perfect motivic homotopy category” and compare it to the classical
homotopy category. For this perfect category, I shall sketch the proof
of an analogous version of the duality conjecture. This is joint work
with Denis-Charles Cisinski, Jeroen Hekking, and Storm Wolters.
Zoom (635 7328 0984, Kenncode: kleinste sechsstellige Primzahl

Categorical Deligne–Langlands correspondence
2025-05-06 14:00 - 15:30 | Darmstadt, Room 401 and Zoom, Schlossgartenstraße 7, Darmstadt, 64289, Germany
Saskia Kern : Talk 3 – Derived categories of quasi-coherent sheaves
Zoom (612 2072 7363, Password: [REDACTED] six digit prime number)

The Shintani–Faddeev modular cocycle: Stark units from q-Pochhammer ratios
2025-05-06 16:00 - 17:00 | Zoom
International Seminar on Automorphic Forms
Zhiyuan Li (SCMS, Fudan University)
The Shintani–Faddeev modular cocycle: Stark units from q-Pochhammer ratios
We give a new interpretation of Stark units associated to real quadratic fields as special “real multiplication values” of a modular cocycle described by complex meromorphic continuation of a simple infinite product. The cocycle encodes the modular transformations of the infinite q-Pochhammer symbol and is related to the Shintani–Barnes double sine funciton and the Faddeev quantum dilogarithm. As a corollary, we describe some intriguing features of the asymptotic behavior of the infinite q-Pochhammer symbol as the modular parameter approaches a real quadratic number.
https://tu-darmstadt.zoom.us/j/68048280736
The password is the first Fourier coefficient of the modular j-function (as digits)

Gromov-Witten theory and real enumerative geometry
2025-05-07 14:15 - 17:00 | Frankfurt, Robert-Mayer-Str. 6-8, Raum 309
14:15 – 15:15 Talk 3: Nicole Müller (Universität Frankfurt): Shifted Symmetric functions and quasimodular forms
15:45 – 16:45 Talk 4: Lukas Schneider (Universität Frankfurt): Quick start to M g,n and its intersection theory

Locally analytic vector bundles on the Fargues-Fontaine-Curve
2025-05-08 11:15 - 13:15 | Heidelberg, Mathematikon, SR 8 and Zoom, INF 205, Heidelberg, Germany
(Equivariant) vector bundles
speaker: Otmar Venjakob (Heidelberg)

Anabelian geometry - Daniel Litt "Arithmetic representations of fundamental groups II"
2025-05-08 14:00 - 17:30 | Heidelberg
14:00 – 15:15 Talk 0: Marius Leonhardt (Universität Heidelberg): Introduction
15:45 – 17:00 Talk 1: Benjamin Steklov (Universität Frankfurt): Deformation spaces

Duality in (perfect) motivic homotopy theory
2025-05-08 14:15 - 15:15 | Mainz, Hilbertraum (05-432)
Christian Dahlhausen (Uni Heidelberg)
Abstract: This talk treats a conjectured duality on modules over K-theory in the stable homotopy category of a scheme whose dualising object is given by G-theory. I shall explain a proof of the conjecture for quasi-excellent schemes in characteristic zero. In order to approach the conjecture in positive characteristic, I sketch the construction of a “perfect motivic homotopy category” and compare it to the classical homotopy category. For this perfect category, I shall sketch the proof of an analogous version of the duality conjecture. This is joint work with Denis-Charles Cisinski, Jeroen Hekking, and Storm Wolters.

D-elliptic sheaves and the Hasse principle
2025-05-09 09:00 - 11:00 | Heidelberg, Mathematikon, SR 8 and Zoom, INF 205, Heidelberg, Germany
D-elliptic sheaves
speaker: Theresa Kaiser (Heidelberg)

Refined Chabauty–Kim computations for the thrice-punctured line over Z[1/6]
2025-05-09 13:30 - 14:30 | Heidelberg, Mathematikon, SR A and Livestream
Martin Lüdtke (MPIM Bonn)
Abstract: If X is a curve of genus at least 2 defined over the rational numbers, we know by Faltings’s Theorem that the set X(Q) of rational points is finite but we don’t know how to systematically compute this set. In 2005, Minhyong Kim proposed a new framework for studying rational (or S-integral) points on curves, called the Chabauty–Kim method. It aims to produce p-adic analytic functions on X(Q_p) containing the rational points X(Q) in their zero locus. We apply this method to solve the S-unit equation for S={2,3} and computationally verify Kim’s Conjecture for many choices of the auxiliary prime p.
