Departement Mathematik

Algebraic geometry and moduli seminar

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Herbstsemester 2021

Datum / Zeit Referent:in Titel Ort
27. August 2021
16:30-17:45 		Dr. Carl Lian
HU Berlin
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Algebraic Geometry and Moduli Seminar

Titel Enumerating pencils on curves with moving ramification
Referent:in, Affiliation Dr. Carl Lian, HU Berlin
Datum, Zeit 27. August 2021, 16:30-17:45
Ort HG G 43
Abstract We consider the general problem of enumerating branched covers of the projective line from a fixed general curve subject to ramification conditions at possibly moving points. Equivalently, these are degrees of Hurwitz spaces over moduli spaces of curves parametrizing the pointed domain of a cover. Our main computations are in genus 1; the theory of limit linear series allows one to reduce to this case. We first obtain a simple formula for a weighted count of pencils on a fixed elliptic curve E, where base-points are allowed. We then deduce, using an inclusion-exclusion procedure, formulas for the numbers of maps E->P^1 with moving ramification conditions. A striking but still-mysterious consequence is the invariance of these counts under a certain involution. Time permitting, I will also speculate on extending these calculations to more general Hurwitz cycles.
Enumerating pencils on curves with moving ramificationread_more
HG G 43
1. September 2021
19:00-20:15 		Samuel Stark
Imperial College
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Algebraic Geometry and Moduli Seminar

Titel Two relations for the virtual fundamental classes of Quot schemes of surfaces
Referent:in, Affiliation Samuel Stark, Imperial College
Datum, Zeit 1. September 2021, 19:00-20:15
Ort HG G 43
Abstract I will discuss two results on the Quot scheme Quot^l_S(E) of length l quotients of a locally free sheaf E on a surface S.The first result states that for certain S, the virtual fundamental class of Quot^l_S(E) equals the fundamental class of the subscheme Quot^l_C(E|_C), where C is a canonical curve in S. This generalises a result of D. Oprea and R. Pandharipande. The second result describes the behaviour of Quot^l_S(E) in the presence of an exact sequence 0 → E' → E → E'' → 0; it says that the Euler class of the tautological sheaf associated to E'* takes the virtual fundamental class of Quot^l_S(E) to the one of the subscheme Quot^l_S(E'').
Two relations for the virtual fundamental classes of Quot schemes of surfacesread_more
HG G 43
* 13. September 2021
18:30-19:45 		Prof. Dr. Eric Zaslow
Northwestern University
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Algebraic Geometry and Moduli Seminar

Titel The proper Landau-Ginzburg potential is the open mirror map
Referent:in, Affiliation Prof. Dr. Eric Zaslow, Northwestern University
Datum, Zeit 13. September 2021, 18:30-19:45
Ort Zoom
Abstract I will discuss toric Fano surfaces in the complement of a smooth anticanonical divisor and their mirror Landau-Ginzburg theories. I will focus on relations between open Gromov-Witten invariants of fibers of the Gross fibration, relative invariants, scattering diagrams and broken lines, tropical curves, superpotentials and wall crossing. This joint work with Tim Graefnitz and Helge Ruddat builds on works of Chan, Lau, Leung, Tseng; the wall crossing takes its cue from the work Gross, Pandharipande, Siebert.
The proper Landau-Ginzburg potential is the open mirror mapread_more
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17. September 2021
16:00-17:15 		Dr. Arkadij Bojko
ETH Zürich
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Algebraic Geometry and Moduli Seminar

Titel Wall-crossing for Quot schemes
Referent:in, Affiliation Dr. Arkadij Bojko, ETH Zürich
Datum, Zeit 17. September 2021, 16:00-17:15
Ort HG G 43
Abstract In my recent work, I have studied virtual integrals over Hilbert schemes on Calabi--Yau fourfolds and noticed a universal transformation relating them to analogous integrals for elliptic surfaces and curves. This suggested that similar methods could be applied to study the virtual classes of Quot-schemes for any vector bundle in lower dimensions. Parallelly, we construct and investigate VFC for fourfolds with some restriction on the vector bundles of which we take quotients. All that follows relies on a wall-crossing conjecture that Joyce is currently working on.From a small piece of initial data, we determine the [Quot_Y(E,n)]^{\text{vir}}, where Y is any curve, surface or Calabi--Yau fourfold. We then use this to obtain natural generalizations of results that where known when E is trivial. This includes:
- Segre--Verlinde correspondence,
- rationality of certain generating series.
We also find some new surprising symmetries: An interesting observation made by Stark predicted using geometric arguments that virtual characteristics in the two fold case only depend on $\text{rk}(E)$. We are able to show a generalization of this - the virtual cobordism class depends only on $\text{rk}(E)$. A similar statement can be made for fourfolds due to existence of a universal transformation relating integrals to the ones for surfaces as in my previous work.
Finally, we study a new symmetry for Segre/Verlinde series for $Y$ a curve, surface or a fourfold which is a more natural variant of the one observed by Arbesfeld--Johnson--Lim--Oprea--Padnharipande.
Wall-crossing for Quot schemesread_more
HG G 43
* 20. September 2021
18:30-19:45 		Prof. Dr. Renzo Cavalieri
Colorado State University
Details

Algebraic Geometry and Moduli Seminar

Titel The integral Chow ring of stable maps to projective space
Referent:in, Affiliation Prof. Dr. Renzo Cavalieri, Colorado State University
Datum, Zeit 20. September 2021, 18:30-19:45
Ort Zoom
Abstract We give an efficient presentation of the Chow ring with integral coefficients of the open part of the moduli space of rational maps of odd degree to projective space. A less fancy description of this space has its closed points correspond to equivalence classes of (r+1)-tuples of degree d polynomials in one variable with no common positive degree factor. We identify this space as a GL(2,C) quotient of an open set in a projective space, and then obtain a (highly redundant) presentation by considering an envelope of the complement. A combinatorial analyis then leads us to eliminating a large number of relations, and to express the remaining ones in generating function form for all dimensions. The upshot of this work is to observe the rich combinatorial structure contained in the Chow rings of these moduli spaces as the degree and the target dimension vary. This is joint work with Damiano Fulghesu.
The integral Chow ring of stable maps to projective spaceread_more
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24. September 2021
16:00-17:15 		Tim Bülles
ETH Zürich
Details

Algebraic Geometry and Moduli Seminar

Titel Weyl symmetry for curve counting invariants via spherical twists
Referent:in, Affiliation Tim Bülles, ETH Zürich
Datum, Zeit 24. September 2021, 16:00-17:15
Ort HG G 43
Abstract The curve counting invariants of Calabi—Yau threefolds exhibit symmetries induced by the action of derived autoequivalences. I will give a brief overview of the subject and explain some recent development. In joint work with M. Moreira we obtain the Weyl symmetry along a ruled divisor, a new rationality result and functional equation for the generating function of stable pairs invariants. The underlying derived autoequivalence involves spherical twists.
Weyl symmetry for curve counting invariants via spherical twistsread_more
HG G 43
1. Oktober 2021
16:00-17:15 		Dirk van Bree
University of Utrecht
Details

Algebraic Geometry and Moduli Seminar

Titel Virasoro contraints for the moduli space of stable sheaves on a surface
Referent:in, Affiliation Dirk van Bree, University of Utrecht
Datum, Zeit 1. Oktober 2021, 16:00-17:15
Ort HG G 43
Abstract The Virasoro constraints are a well-known conjecture in GW-theory. Recently, Moreira, Oblomkov, Okounkov and Pandharipande formulated versions for the PT-theory of a 3-fold and the Hilbert scheme of points on a surface. I will introduce a version of this conjecture for the moduli space of stable sheaves on a surface, generalising the Hilbert scheme case. Then I will explain how to verify this conjecture in a few explicit toric cases. This involves a combinatorial description of equivariant sheaves which is originally due to Klyachko.
Virasoro contraints for the moduli space of stable sheaves on a surfaceread_more
HG G 43
* 4. Oktober 2021
18:30-19:45 		Prof. Dr. Richard Thomas
Imperial College
Details

Algebraic Geometry and Moduli Seminar

Titel Higher rank DT theory from curve counting
Referent:in, Affiliation Prof. Dr. Richard Thomas, Imperial College
Datum, Zeit 4. Oktober 2021, 18:30-19:45
Ort Zoom
Higher rank DT theory from curve counting
Zoom
6. Oktober 2021
13:30-14:45 		Prof. Dr. Andras Stipsicz
Rényi Institute, Budapest
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Algebraic Geometry and Moduli Seminar

Titel On exotic 4-manifolds
Referent:in, Affiliation Prof. Dr. Andras Stipsicz, Rényi Institute, Budapest
Datum, Zeit 6. Oktober 2021, 13:30-14:45
Ort HG G 43
Abstract Topological 4-manifolds tend to have infinitely many different smooth structure (or have none). In the closed case these ‘exotic’ structures are distinguished by gauge theoretic invariants (like the Seiberg-Witten invariants), which invariants say very little in the most interesting case: for the 4-dimensional sphere. In the lecture we review some constructions providing potential examples of exotic spheres, and examine the limitations of distinguishing smooth structures based on sliceness properties of knots and links in manifolds with boundary naturally associated to the closed manifolds. This is joint work with Alberto Cavallo.
On exotic 4-manifoldsread_more
HG G 43
8. Oktober 2021
16:00-17:15 		Dr. Sam Molcho
ETH Zürich
Details

Algebraic Geometry and Moduli Seminar

Titel Line bundles on nodal curves and the DR cycle I
Referent:in, Affiliation Dr. Sam Molcho, ETH Zürich
Datum, Zeit 8. Oktober 2021, 16:00-17:15
Ort HG G 43
Abstract In this series of two talks, I will discuss aspects of our approach with Holmes,Pandharipande, Pixton and Schmitt, aiming to give formulas for the higher double ramification cycles. In the first talk, I will discuss the structure of line bundles on a family of nodal curves, and how this perspective connects compactifications of the universal Jacobian variety to the double ramification cycle. In the second talk, I will explain how, based on the notion of a stability condition, one can construct such compactifications with remarkable properties, ultimately leading to a formula.
Line bundles on nodal curves and the DR cycle Iread_more
HG G 43
13. Oktober 2021
13:30-14:45 		Younghan Bae
ETH Zürich
Details

Algebraic Geometry and Moduli Seminar

Titel Descendent invariants for stable pairs on Calabi-Yau fourfolds
Referent:in, Affiliation Younghan Bae, ETH Zürich
Datum, Zeit 13. Oktober 2021, 13:30-14:45
Ort HG G 43
Abstract Eguchi, Hori and Xiong predicted that the Gromov-Witten invariants satisfy a set of recursive relations which is now called the Virasoro constraint. Using the GW/Pair correspondence, Moreira, Oblomkov, Okounkov and Pandharipande studied Virasoro conjecture for stable pairs on Fano threefolds. In concrete terms, Virasoro conjecture on stable pairs predicts certain relations on decendent invariants on the space of stable pairs. In this talk, we conjecture Virasoro constraints for stable pairs on Calabi-Yau fourfolds and see some evidences of the conjecture. This is a work in progress with Woonam Lim and Miguel Moreira.
Descendent invariants for stable pairs on Calabi-Yau fourfoldsread_more
HG G 43
* 18. Oktober 2021
18:30-19:45 		Dr. Ben Davison
University of Edinburgh
Details

Algebraic Geometry and Moduli Seminar

Titel The decomposition theorem for 2-Calabi-Yau categories
Referent:in, Affiliation Dr. Ben Davison, University of Edinburgh
Datum, Zeit 18. Oktober 2021, 18:30-19:45
Ort Zoom
Abstract Examples of 2CY categories include the category of coherent sheaves on a K3 surface, the category of Higgs bundles, and the category of modules over preprojective algebras or fundamental group algebras of compact Riemann surfaces. Let p:M->N be the morphism from the stack of semistable objects in a 2CY category to the coarse moduli space. I'll explain, using cohomological DT theory, formality in 2CY categories, and structure theorems for good moduli stacks, how to prove a version of the BBDG decomposition theorem for the exceptional direct image of the constant sheaf along p, even though none of the usual conditions for the decomposition theorem apply: p isn't projective or representable, M isn't smooth, the constant mixed Hodge module complex $\mathbb{Q}_M$ isn't pure... As applications, I'll explain a proof of Halpern-Leistner's conjecture on the purity of stacks of coherent sheaves on K3 surfaces, and if time permits, a (partly conjectural) way to extend nonabelian Hodge theory to Betti/Dolbeault stacks.
The decomposition theorem for 2-Calabi-Yau categoriesread_more
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22. Oktober 2021
16:00-17:15 		Dr. Sam Molcho
ETH Zürich
Details

Algebraic Geometry and Moduli Seminar

Titel Line bundles on nodal curves and the DR cycle II
Referent:in, Affiliation Dr. Sam Molcho, ETH Zürich
Datum, Zeit 22. Oktober 2021, 16:00-17:15
Ort HG G 43
Abstract In this series of two talks, I will discuss aspects of our approach with Holmes,Pandharipande, Pixton and Schmitt, aiming to give formulas for the higher double ramification cycles. In the first talk, I will discuss the structure of line bundles on a family of nodal curves, and how this perspective connects compactifications of the universal Jacobian variety to the double ramification cycle. In the second talk, I will explain how, based on the notion of a stability condition, one can construct such compactifications with remarkable properties, ultimately leading to a formula.
Line bundles on nodal curves and the DR cycle IIread_more
HG G 43
* 25. Oktober 2021
18:30-19:45 		Prof. Dr. Burt Totaro
UCLA
Details

Algebraic Geometry and Moduli Seminar

Titel Varieties of general type with doubly exponential asymptotics
Referent:in, Affiliation Prof. Dr. Burt Totaro, UCLA
Datum, Zeit 25. Oktober 2021, 18:30-19:45
Ort Zoom
Abstract We construct smooth projective varieties of general type with the smallest known volume and others with the most known vanishing plurigenera in high dimensions. The optimal volume bound is expected to decay doubly exponentially with dimension, and our examples achieve this decay rate. We also consider the analogous questions for other types of varieties. For example, in every dimension we conjecture the terminal Fano variety of minimal volume, and the canonical Calabi-Yau variety of minimal volume. In each case, our examples exhibit doubly exponential behavior. (Joint work with Louis Esser and Chengxi Wang.)
Varieties of general type with doubly exponential asymptoticsread_more
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28. Oktober 2021
16:00-17:15 		Dr. Woonam Lim
ETH Zürich
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Algebraic Geometry and Moduli Seminar

Titel Wall-crossing formula for pairs on Calabi-Yau 4-folds
Referent:in, Affiliation Dr. Woonam Lim, ETH Zürich
Datum, Zeit 28. Oktober 2021, 16:00-17:15
Ort ITS
Abstract Recently, Joyce proposed a wall-crossing framework for DT4 virtual classes using the language of a vertex algebra. On Calabi-Yau 4-folds, there are pair theories of dimensions at most 2 for various stability conditions. Assuming the wall-crossing conjecture, we prove the expected form of DT/PT curve correspondence by modding out the Hilbert scheme of points contribution. For DT/PT0 surface correspondence, however, we find that this is not sufficient in general. We explain how the extra corrections involving descendants of c_3(X) solve this problem. If time permits, I will try to explain what are the main difficulties in formulating PT0/PT1 surface correspondence. This is a joint work in progress with Younghan Bae, Arkadij Bojko.
Wall-crossing formula for pairs on Calabi-Yau 4-foldsread_more
ITS
* 1. November 2021
17:30-18:45 		Dr. Dori Bejleri
Harvard University
Details

Algebraic Geometry and Moduli Seminar

Titel Wall crossing for moduli of stable log varieties
Referent:in, Affiliation Dr. Dori Bejleri, Harvard University
Datum, Zeit 1. November 2021, 17:30-18:45
Ort Zoom
Abstract Stable log varieties or stable pairs (X,D) are the higher dimensional generalization of pointed stable curves. They form proper moduli spaces which compactify the moduli space of normal crossings, or more generally klt, pairs. These stable pairs compactifications depend on a choice of parameters, namely the coefficients of the boundary divisor D. In this talk, after introducing the theory of stable log varieties, I will explain the wall-crossing behavior that governs how these compactifications change as one varies the coefficients. I will also discuss some examples and applications. This is joint work with Kenny Ascher, Giovanni Inchiostro, and Zsolt Patakfalvi.
Wall crossing for moduli of stable log varietiesread_more
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* 8. November 2021
18:30-19:45 		Prof. Dr. Aaron Pixton
University of Michigan
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Algebraic Geometry and Moduli Seminar

Titel Formulas for double-double ramification cycles
Referent:in, Affiliation Prof. Dr. Aaron Pixton, University of Michigan
Datum, Zeit 8. November 2021, 18:30-19:45
Ort Zoom
Abstract The double-double ramification cycle parametrizes curves of genus g admitting two maps to the projective line with specified ramification profiles over two points. This cycle is easy to define in families of smooth curves, but much more subtle for general stable curves. I will discuss some special cases in which a formula for the double-double ramification cycle is now known. This is joint work with David Holmes, Sam Molcho, Rahul Pandharipande, and Johannes Schmitt.
Formulas for double-double ramification cyclesread_more
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10. November 2021
13:30-14:45 		Dr. Longting Wu
MPI Bonn
Details

Algebraic Geometry and Moduli Seminar

Titel A new approach to the operator formalism for the equivariant Gromov-Witten theory of the cap
Referent:in, Affiliation Dr. Longting Wu, MPI Bonn
Datum, Zeit 10. November 2021, 13:30-14:45
Ort HG G 43
Abstract The operator formalism for the equivariant Gromov-Witten theory of P^1 relative to one point plays an important role in the proof of Virasoro constraints for curves. It was originally deduced by Okounkov and Pandharipande via a long and complicated induction. In this talk, we will give a new and simple approach to the operator formalism based on Johnson's operator formalism for the equivariant Gromov-Witten theory of orbifold P^1. This is a work in progress with Ajith Urundolil Kumaran.
A new approach to the operator formalism for the equivariant Gromov-Witten theory of the capread_more
HG G 43
* 17. November 2021
13:30-14:45 		Dr. Xiaowen Hu
Sun Yat-Sen University (Guangzhou)
Details

Algebraic Geometry and Moduli Seminar

Titel On the big quantum cohomology of Fano complete intersections
Referent:in, Affiliation Dr. Xiaowen Hu, Sun Yat-Sen University (Guangzhou)
Datum, Zeit 17. November 2021, 13:30-14:45
Ort Zoom
Abstract We will report a recent progress on quantum cohomology of Fano complete intersections in projective spaces. We will introduce the square root recursion conjecture, and a puzzle in odd dimensions, and some ad hoc methods for cubic hypersurfaces. For even dimensional intersections of two quadrics as a kind of exceptional complete intersections, we will explain the special feature of a genus 0 invariant of odd length, and in 4 dimension how it is related to enumerative geometry.
On the big quantum cohomology of Fano complete intersectionsread_more
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* 17. November 2021
15:00-16:15 		Dr. Pierrick Bousseau
CNRS and University of Paris-Saclay
Details

Algebraic Geometry and Moduli Seminar

Titel Gromov-Witten theory of complete intersections
Referent:in, Affiliation Dr. Pierrick Bousseau, CNRS and University of Paris-Saclay
Datum, Zeit 17. November 2021, 15:00-16:15
Ort Zoom
Abstract I will describe an inductive algorithm computing Gromov-Witten invariants in all genera with arbitrary insertions of all smooth complete intersections in projective space. The main idea is to show that invariants with insertions of primitive cohomology classes are controlled by their monodromy and by invariants defined without primitive insertions but with imposed nodes in the domain curve. To compute these nodal Gromov-Witten invariants, we introduce the new notion of nodal relative Gromov-Witten invariants. This is joint work with Hülya Argüz, Rahul Pandharipande, and Dimitri Zvonkine (arxiv:2109.13323).
Gromov-Witten theory of complete intersectionsread_more
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19. November 2021
16:00-17:15 		Dr. Kaloyan Slavov
ETH Zürich
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Algebraic Geometry and Moduli Seminar

Titel A criterion for full monodromy
Referent:in, Affiliation Dr. Kaloyan Slavov, ETH Zürich
Datum, Zeit 19. November 2021, 16:00-17:15
Ort HG G 43
Abstract Let G be a subgroup of the symmetric group S_d. Suppose the proportion of elements in G with no fixed points equals the proportion of elements in S_d with no fixed points. Then we prove G=S_d. As an application, we give a criterion for a map to have full monodromy. This is joint work with Bjorn Poonen.
A criterion for full monodromyread_more
HG G 43
* 22. November 2021
18:30-19:45 		Prof. Dr. Georg Oberdieck
Universität Bonn
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Algebraic Geometry and Moduli Seminar

Titel From K3 surfaces to Hilbert schemes and back again
Referent:in, Affiliation Prof. Dr. Georg Oberdieck, Universität Bonn
Datum, Zeit 22. November 2021, 18:30-19:45
Ort Zoom
Abstract I will discuss the relationship between three different counting theories associated to a K3 surface S: (i) Gromov-Witten theory of the Hilbert scheme of points of S with complex structure of the source curve fixed to be an elliptic curve E with some rational tails, (ii) Donaldson-Thomas theory of SxE, (iii) Virtual Euler characteristics of Quot schemes of stable sheaves on the K3 surfaces. This leads to new evaluations of these virtual Euler numbers, and to multiple cover formulas for all three theories.
From K3 surfaces to Hilbert schemes and back againread_more
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26. November 2021
16:00-17:15 		Dr. Thorsten Schimannek
University of Vienna
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Algebraic Geometry and Moduli Seminar

Titel Torus fibered Calabi-Yau spaces, modular curves, and Gopakumar-Vafa invariants with discrete charges
Referent:in, Affiliation Dr. Thorsten Schimannek, University of Vienna
Datum, Zeit 26. November 2021, 16:00-17:15
Ort HG G 43
Abstract The A-model topological string partition functions on torus fibered Calabi-Yau threefolds admit an expansion in terms of (weak) Jacobi forms.This can be seen as a consequence of a Gamma_1(N) action on the complexified volumes of curves that is generated by certain auto-equivalences of the derived category of coherent sheaves. Here the level N of the group is the degree of the fiber as a genus one curve over the function field of the base. We argue that, as a result, the complexified Kähler moduli space reduces in the large base limit to the Gamma_1(N) modular curve. The cusps of the modular curve then correspond to additional large volume limits and the partition functions at those points are related by Atkin-Lehner involutions. Motivated by Higgs transitions in M- and F-theory, we interpret the underlying geometries as non-commutative resolutions of torus fibrations that share the same Jacobian fibration. We then propose an enumerative interpretation in terms of Gopakumar-Vafa invariants with discrete charges that combines the partition functions of different non-commutative resolutions of the same singular torus fibration.
Torus fibered Calabi-Yau spaces, modular curves, and Gopakumar-Vafa invariants with discrete chargesread_more
HG G 43
3. Dezember 2021
16:00-17:15 		Dr. Honglu Fan
Université de Genève
Details

Algebraic Geometry and Moduli Seminar

Titel Some new thoughts on localization on masterspaces
Referent:in, Affiliation Dr. Honglu Fan, Université de Genève
Datum, Zeit 3. Dezember 2021, 16:00-17:15
Ort HG G 43
Abstract I will talk about a family of new masterspaces (by J. Guéré) that computes quintic 3-fold Gromov-Witten invariants when d>(2g-2)/5. Although they do not produce new knowledge about quintic invariants, I will try to explain why they have some interesting computational features and get us closer to the physicists' predictions than using my original masterspace in 1712.03573. This is an active discussion with J.Guéré, S. Guo and H. Lho. If time permits, I can also mention a very recent idea suggested by G. Oberdieck to me about applying those masterspace constructions on elliptic fibrations.
Some new thoughts on localization on masterspacesread_more
HG G 43
* 13. Dezember 2021
18:30-19:45 		Samir Canning
UC San Diego
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Algebraic Geometry and Moduli Seminar

Titel The Chow rings of moduli spaces of elliptic surfaces
Referent:in, Affiliation Samir Canning, UC San Diego
Datum, Zeit 13. Dezember 2021, 18:30-19:45
Ort Zoom
Abstract For each nonnegative integer N, Miranda constructed a coarse moduli space of elliptic surfaces with section over the projective line with fundamental invariant N. I will explain how to compute the Chow rings of these moduli spaces when N is at least 2. The Chow rings exhibit many properties analogous to those expected for the tautological ring of the moduli space of curves: they satisfy analogues of Faber's conjectures, and they exhibit a stability property as N goes to infinity. When N=2, these elliptic surfaces are K3 surfaces polarized by a hyperbolic lattice. I will explain how the computation of the Chow ring confirms a special case of a conjecture of Oprea and Pandharipande on the structure of the tautological rings of moduli spaces of lattice polarized K3 surfaces. This is joint work with Bochao Kong.
The Chow rings of moduli spaces of elliptic surfacesread_more
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* 10. Januar 2022
17:30-18:45 		Borislav Mladenov
Imperial College
Details

Algebraic Geometry and Moduli Seminar

Titel Degeneration of Ext and formality of RHom associated to holomorphic Lagrangian subvarieties
Referent:in, Affiliation Borislav Mladenov, Imperial College
Datum, Zeit 10. Januar 2022, 17:30-18:45
Ort Zoom
Degeneration of Ext and formality of RHom associated to holomorphic Lagrangian subvarieties
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* 17. Januar 2022
17:30-18:45 		Prof. Dr. Lothar Göttsche
ICTP Trieste
Details

Algebraic Geometry and Moduli Seminar

Titel Blowup formulas, strange duality and generating functions for Segre and Verlinde numbers of surfaces
Referent:in, Affiliation Prof. Dr. Lothar Göttsche, ICTP Trieste
Datum, Zeit 17. Januar 2022, 17:30-18:45
Ort Zoom
Blowup formulas, strange duality and generating functions for Segre and Verlinde numbers of surfaces
Zoom

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