The RINDSeminar (RheinIsarNeckarDonau) is a joint online video seminar series on theoretical and mathematical physics organized together by the JGU Mainz, the LMU Munich, the University of Heidelberg, and the University of Vienna via Zoom or BigBlueButton.
If you are interested in joining, please contact Mascha Ringe or one of the organizers for the Zoom or BigBlueButton credentials.
If you would like to join our mailing list for announcements and reminders, please contact Mascha Ringe or send an email as follows to sympa@lists.unimainz.de and confirm by clicking the link in the email you receive:
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Time: Mondays at 4:15 pm (UTC + 1)
Schedule:
Programm für das Wintersemester 2022/2023
Mondays, 16 Uhr c.t.
U. Mainz, LMU Munich, U. Heidelberg, U. Vienna
24.10.22  Albrecht Klemm, Bonn U.  
Recently it has been realized that the parameter dependence of
Feynman integrals in dimensional regularisation can be calculated
explicitly using period and chain integrals of suitably chosen
CalabiYau motives, where the transcendentality weight of
the motive is proportional to the dimension of the Calabi Yau
geometry and the loop order of the Feynman graphs. We exemplify
this for the Banana graphs, the Ice Cone graphs and the Train Track graphs
in two dimensions. In the latter case there is a calculational very useful
relation between the differential realisation of the
Yangian symmetries and the PicardFuchs system of compact
CalabiYau spaces M as well as between the physical correlations
functions and the quantum volume of the manifolds W that are the
mirrors to M.  
16 Uhr c.t., Munich, at Zoom  

31.10.22  Lorenz Eberhardt, IAS  
I will revisit string oneloop amplitudes in this talk. After reviewing the basics, I will explain how Witten’s iepsilon prescription gives a manifestly convergent representation of the amplitude. I will then consider the imaginary part of the amplitude and show directly that it satisfies the standard field theory cutting rules. This leads to an exact representation of the imaginary part of the amplitude. I will also discuss physical properties of the imaginary part such as the singularity structure of the amplitude, its Regge and high energy fixedangle behaviour and lowspin dominance. Finally, I will tease how Rademacher’s contour can be used to evaluate the full oneloop open string amplitude exactly in terms of a convergent infinite sum.  
16 Uhr c.t., at Zoom  

14.11.22  Raghu Mahajan, Stanford U.  
We use insights from string field theory to analyze and cure the divergences in the cylinder diagram in minimal string theory, with both boundaries lying on a ZZ brane. Minimal string theory refers to the theory of twodimensional gravity coupled to a minimal model CFT that serves as the matter sector; it includes JT gravity as a limiting case. ZZ branes are akin to Dinstantons, and give rise to features that reflect the underlying discreteness of the dual theory. The exponential of the cylinder diagram represents the oneloop determinant around the instanton saddle. The finite result for this oneloop constant computed using the string field theory procedure agrees precisely with independent calculations in the dual doublescaled matrix integrals performed by several authors many years ago.  
16 Uhr c.t., at Zoom  

28.11.22  Enno Keßler, MPIM Bonn  
Jholomorphic curves or pseudoholomorphic curves are maps from Riemann
surfaces to symplectic manifolds satisfying the CauchyRiemann equations.
Jholomorphic curves are of great interest because they allow to construct
invariants of symplectic manifolds and those invariants are deeply related to
topological superstring theory. A crucial step towards Gromov–Witten
invariants is the compactification of the moduli space of Jholomorphic curves
via stable maps which was first proposed by Kontsevich and Manin.
In this talk, I want to report on a supergeometric generalization of J
holomorphic curves and stable maps where the domain is a super Riemann
surface. Super Riemann surfaces have first appeared as generalizations of
Riemann surfaces with anticommutative variables in superstring theory. Super
Jholomorphic curves couple the equations of classical Jholomorphic curves
with a Dirac equation for spinors and are critical points of the
superconformal action. The compactification of the moduli space of super J
holomorphic curves via super stable maps might, in the future, lead to a
supergeometric generalization of GromovWitten invariants.
Based on arXiv:2010.15634 [math.DG] and arXiv:1911.05607 [math.DG], joint with
Artan Sheshmani and ShingTung Yau.  
16 Uhr c.t., at Zoom  

05.12.22  Nikita Nekrasov, Stony Brook U.  
CalogeroMoserSutherland system of particles is a prototypical example of a system with fractional statistics. I review the old and new connections of this system to (super) YangMills theory in various dimensions.  
16 Uhr c.t., at Zoom  

12.12.22  Ida Zadeh, JGU Mainz  
I will discuss compactification of the heterotic string on the smooth, flat 3manifold T3/Z2, without supersymmetry. The low energy dynamics of the corresponding ten dimensional heterotic supergravity will be described. The semiclassical theory has both Coulomb and Higgs branches of nonsupersymmetric vacua. An exact worldsheet description of the compactification will then be presented using the framework of asymmetric orbifolds of T3, where the orbifold generator involves a Nikulin nonsymplectic involution of the even selfdual lattice of signature (19,3). This construction gives a novel conformal field theory description of the semiclassical field theory moduli space and reveals a rich pattern of transitions amongst Higgs and Coulomb branches.  
16 Uhr c.t., at Zoom  

19.12.22  Niccolo Cribiori & Ralph Blumenhagen, Max Planck Institut for Physics, Munich  
The absence of global symmetries is widely believed to be a principle of quantum gravity. Recently, it has been generalised to the statement that the cobordism group of quantum gravity must be trivial. Indeed, a nontrivial group detects a higherform global symmetry, which has then to either be gauged or broken. In the case in which it is broken, defects have to be introduced into the setup. These can be endoftheworld branes furnishing a dynamical realization of cobordism, of which we will provide a new concrete example. In the case in which the symmetry is gauged, we will argue that there is a nontrivial interplay between cobordism and Ktheory, leading to the construction of type IIB/Ftheory tadpoles from a bottomup perspective. This interpretation of cobordism and Ktheory as charges in quantum gravity can be given further support when passing from groups of the point to groups of a generic manifold X. We will argue that these more general groups have a natural interpretation in terms of the dimensional reduction of the theory on X. A systematic analysis can possibly lead to the prediction of new contributions to string theory tadpoles.  
16 Uhr c.t., LMU Munich (Room A348), at Zoom  

09.01.23  Nicolo Piazzalunga, Uppsala U.  
I'll introduce the higherrank DonaldsonThomas theory for toric CalabiYau threefolds, within the setting of equivariant Ktheory.
I'll present a factorization conjecture motivated by Physics.
As a byproduct, I'll discuss some novel properties of equivariant volumes, as well as their generalizations to genuszero GromovWitten theory of noncompact toric varieties.  
16 Uhr c.t., Munich, at Zoom  

30.01.23  Konstantin Wernli, University of Southern Denmark  
In the BatalinVilkovisky (BV) formalism, one can define a perturbative (i.e. given by Feynman graphs and rules) partition function $Z(x_0)$ for any choice of classical background (solution to EulerLagrange (EL) equations) $x_0$. In some examples one can extract from $Z$ a volume form on the smooth part of the moduli space of solutions to EL equations, and compare its integral with nonperturbative approaches to quantization. I will review this construction, some results from examples in the literature and ongoing joint work with P. Mnev about the behaviour at singular points $x_0$.  
16 Uhr c.t., at Zoom  

06.02.23  Renann Lipinski Jusinskas, Prague  
In this talk I will present a worldsheet model obtained from "twisting" the target space CFT of conventional string theory. The physical spectrum becomes finite and corresponds to the massless spectrum of closed strings plus a single massive level of the open string. The underlying idea is to explore the field/string theory interface in both directions. On one hand, the goal is to generate effective field theories describing massive higher spins using worldsheet methods. Conversely, we may try to use field theory methods to obtain a systematic description of string scattering amplitudes using field theory methods.  
16 Uhr c.t., Munich, Theresienstr. 37A, R. 348, at Zoom  

Joint seminar series on Mathematical Physics and String Theory 
Koordination:  Kontakt: 
Ilka Brunner (LMU München)  Mascha Ringe userID: mringe 

Past seminars winter 2022/2023
06.02. Renann Lipinski Jusinskas (Prague) "Asymmetrically twisted strings"
30.01. Konstantin Wernli (University of Southern Denmark) "On Globalization of Perturbative Partition Functions in the Batalinvilkovisky formalism"
09.01. Nicolo Piazzalunga (Uppsala U.) "The index of Mtheory"
19.12. Niccolo Cribiori & Ralph Blumenhagen (Max Planck Institute for Physics, Munich) "Cobordism, Ktheory and tadpoles"
12.12. Ida Zadeh (JGU Mainz) "Heterotic Strings on T3/Z2, Nikulin involutions and Mtheory"
05.12. Nikita Nekrasov (Stony Brook U.) "Anyons hiding in gauge theory in two, three and four dimensions"
28.11. Enno Keßler (MPIM Bonn) "Super stable maps"
14.11. Raghu Mahajan (Stanford U.) "ZZ instanton amplitudes in minimal string theory at oneloop order"
31.10. Lorenz Eberhardt (IAS) "Unitarity cuts of the worldsheet"
24.10. Albrecht Klemm (Bonn U.) "Feynman integrals, CalabiYau geometries and integrable systems"

Past seminars summer 2022
18.07. Hossein Movasati (IMPA, Brasil) "Modular and automorphic forms and beyond"
27.06. Sara Pasquetti (U. of MilanoBicocca) "Rethinking mirror symmetry as a local duality on fields"
20.06. Heeyeon Kim (Rutgers U.) "Path integral deviations of Ktheoretic Donaldson invariants"
30.05. Maxim Zabzine (Uppsala U.) "The index of Mtheory and equivariant volumes"
23.05. Leonardo Rastelli (Stony Brook U.) "On the 4D SCFTs/VOAs correspondence"
16.05. Fabian Hahner (Heidelberg U.) "Derived pure spinor superfields"
09.05. Urs Schreiber (Prague U.) "Anyonic Defect Branes and Conformal Blocks in Twisted Equivariant Differential KTheory"
02.05. Murad Alim (Hamburg U.) "Nonperturbative quantum geometry, resurgence and BPS structures"
25.04. Minhyong Kim (U. of Warwick) "Quantum Field Theory as Mathematical Formalism: The Case of Arithmetic Geometry"

Past seminars winter 2021/2022
07.02. Jakob Palmkvist (Orebro U.) "Nonlinear realisations of Lie superalgebras"
31.01. Tudor Dimofte (U. Davies & Edinburgh) "A QFT for nonsemisimple TQFT"
24.01. Surya Raghavendran (Perimeter) "Twisted Sduality"
17.01. Daniel Roggenkamp (U. Mannheim) "Defects and affine RozanskyWitten models"
10.01. Eric Sharpe (Virginia Tech.) "An introduction to decomposition"
20.12. Yongbin Ruan (Zhejiang University) "Geometric Langlands and coadjoint orbits"
13.12. Justin Hilburn (Perimeter) "2Categorical 3d Mirror Symmetry"
06.12. Mykola Dedushenko "Quantum algebras and SUSY interfaces"
29.11. Kevin Costello (Perimeter) "Selfdual YangMills and anomaly cancellation on twistor space"
22.11. Ingmar Saberi (LMU) "Twisted elevendimensional supergravity and exceptional Lie algebras"
15.11. Pavel Putrov (ICTP Trieste) "Nonsemisimple TQFTs and BPS qseries"
25.10. Michele Schiavina (ETH Zurich) "BVBFV approach to General Relativity"

Past seminars summer 2021
05.07. Jan Manschot (Dublin) "Topological correlators of N=2* YangMills theory"
21.06. Johanna Knapp (Melbourne) "Genus 1 fibered CalabiYau 3folds with 5sections  A GLSM perspective"
14.06. John Huerta (University of Lisbon) "Bundle gerbes on Lie supergroups"
17.05. Cyrill Closset (Birmingham) "Rank1 5d SCFTs: Mapping out the Uplane"
10.05. Lukas Woike (Copenhagen) "Higher structures from modular categories"
03.05. Miguel Montero (Harvard) "Cobordisms, anomalies, and the Swampland"
26.04. Mathew Bullimore(Durham U.)"Towards a Mathematical Definition of the 3d Superconformal Index"
19.04. Francesco Benini (SISSA) "Superconformal Index and Gravitational Path Integral"
12.04. Shota Komatsu (CERN) "Three tales of de Sitter"

Past seminars winter 2020/2021
01.02. Andrea Brini "Quantum geometry and physics of Looijenga pairs"
25.01. Simeon Hellerman "The Large Quantum Number Expansion: Some Recent Developments"
11.01. Kasia Rejzner "BVBFV formalism in perturbative AQFT"
14.12. Dmitri Bykov "Sigma models as GrossNeveu models"
07.12. Susanne Reffert (U. Bern) "The large charge expansion"
30.11. Jörg Teschner (DESY) "PROPOSAL FOR A GEOMETRIC CHARACTERISATION OF TOPOLOGICAL STRING PARTITION FUNCTIONS"
16.11. Owen Gwilliam (U. of Massachusetts) "Centers of higher enveloping algebras and bulkboundary systems"
09.11. Ilka Brunner (LMU) "Flow Defects and Phases of gauged linear sigma models"
02.11. Mathias Traube (MPI Munich) "Cardy Algebras, SewingConstraints and StringNets"
26.10. Theo JohnsonFreyd (Perimeter) "3+1d topological orders with (only) an emergent fermion"
19.10. Chris Beem (Oxford U.) "HallLittlewood Chiral Rings and Derived Higgs Branches"
12.10. Ezra Getzler (Northwestern U.) "Gluing local gauge conditions in BV quantum field theory

Past seminars summer 2020
20.07. Thorsten Schimannek (Vienna U.) "The quantum geometry of genus one fibered CalabiYau threefolds"
13.07. Thomas Creutzig (Alberta) "Algebraic blowup"
29.06. Alberto Cattaneo (Zurich) "HamiltonJacobi and Quantum ChernSimons on Cylinders"
22.06 Simone Noja (Como) "On Some Global and Local Problems in Supergeometry"
15.06. Tomas Prochazka (LMU) "Grassmannian VOAs"
08.06. Ingmar Saberi (Heidelberg) "Holomorphic field theories and higher symmetries"
25.05. Christoph Chiaffrino (LMU) “Planar Quantum AInfinity Algebras”
18.05. Nils Carqueville (Vienna) “An introduction to functorial TQFT with defects”
11.05. Ivo Sachs (LMU) "From BV to string theory and back"