mathematical string theory meeting

Previous southeastern regional mathematical string theory meetings:

Video of many of these talks can be found here, in the string theory folder.

- 20th meeting: Saturday October 13, 2018, at James Madison University.
Group photos
here,
here,
here,
here.
Schedule:
- Friday Oct 12: optional dinnner at, tentatively,
Clementine Cafe (153 S Main St,
Harrisonburg, VA), at 7:30 pm. (If the restaurant's parking lot is full,
note that there is a
municipal parking deck
on the other side of the same block, and after 7 pm, no time limit.)
- Saturday Oct 13: (All talks will be in Physics-Chemistry building room
PHCH2212.)
- 10:00-11:00: Po-Shen Hsin (Princeton),
"2-group global symmetry in QFT":
- Abstract: Quantum field theory can have 2-group symmetry that combines 0-form and 1-form symmetries. I will give examples of QFT with 2-group symmetry. In particular, I will discuss the anomaly of 2-group symmetry, and explore its consequences for the renormalization group flow.
- talk slides (pdf)

- 11:15-12:15: Mykola Dedushenko (Caltech),
"Gluing in QFT and Boundary Localization":
- Abstract: I will revisit the cutting an gluing law in local quantum field theory. In particular, gluing operation in Lagrangian theories can be represented as a path integral over a space of certain 'polarized' boundary conditions. This path integral, although being terribly non-local, can sometimes be simplified in supersymmetric theories using the localization techniques. This allows to obtain interesting gluing formulas that can be further applied to various problems, as will be discussed in more details during the talk.
- photo, photo, photo, photo, photo, photo, photo

- 12:30-2: Lunch,
- 2:00-3:00: Cynthia Keeler
(Arizona State),
"Partition Functions via Quasinormal Mode Methods: AdS, Warped AdS, and
Large Dimensions":
- Abstract: After a review of the quasinormal mode method for partition function calculation developed by Denef, Hartnoll, and Sachdev, we extend the method to consider even-dimensional AdS spaces, Warped AdS spaces, and black holes in the large dimension limit. If time permits, we will also discuss the relationship between the quasinormal mode method and the heat kernel method.
- photo, photo, photo, photo
- talk slides (pdf)

- 3:15-4:15: Fedor Popov (Princeton),
"Traversable wormholes in four dimensions":
- Abstract: We present a wormhole solution in four dimensions. It is a solution of an Einstein Maxwell theory plus charged massless fermions. The fermions give rise to a negative Casimir-like energy, which makes the wormhole possible. It is a long wormhole that does not lead to causality violations in the ambient space. It can be viewed as a pair of entangled near extremal black holes with an interaction term generated by the exchange of fermion fields.
- photo, photo, photo
- talk slides (pptx)

- 4:30-5:30: Andy Royston
(Penn State Fayette).
"Wall crossing from Dirac Zero modes":
- Abstract: In the semiclassical quantization of 4D N=2 super-Yang-Mills, (framed) BPS states are represented by zero mode wavefunctions of certain Dirac-like operators on the moduli space of (singular) monopoles. A direct analysis of these Dirac operators utilizing the asymptotic metric on monopole moduli space leads to a physically intuitive derivation of the primitive wall-crossing formula for BPS states. The derivation holds modulo a technical assumption about the Fredholm properties of these operators. Proving this assumption and showing how it must be modified in the non-primitive case is an open problem that makes contact with recent developments in the mathematics literature on compactifications of monopole moduli spaces on manifolds with corners. Additionally, the physics derivation leads to a surprising prediction: the existence of completely stable non-BPS boundstates. This talk is based on work done in collaboration with Greg Moore and Daniel Brennan.
- photo, photo, photo, photo, photo, photo

- 10:00-11:00: Po-Shen Hsin (Princeton),
"2-group global symmetry in QFT":

- Friday Oct 12: optional dinnner at, tentatively,
Clementine Cafe (153 S Main St,
Harrisonburg, VA), at 7:30 pm. (If the restaurant's parking lot is full,
note that there is a
municipal parking deck
on the other side of the same block, and after 7 pm, no time limit.)
- 19th meeting: Saturday April 7, 2018, at Duke University, in
physics room 130. Group photos
here,
here,
here.
Schedule:
- 10:00-11:00: Daniel Roberts (IAS / FAIR),
"Chaos and the growth of operators"
- Abstract: We will consider (a very small subset of) recent work on quantum chaos. We will connect the butterfly effect to the growth of operators through the lens of different model quantum systems: spin chains, holographic CFTs, and the SYK model. We will also enumerate different diagnostics for chaos including out-of-time-order correlation functions (OTOCs) and discuss different speeds at which information can propagate in quantum systems.
- photo, photo, photo, photo, photo

- 11:15-12:15: Laura Schaposnik (Univ Illinois Chicago),
"On Cayley and Langlands type correspondences for Higgs bundles"
- Abstract: The Hitchin fibration is a natural tool through which one can understand the moduli space of Higgs bundles and its interesting subspaces (branes). After reviewing the type of questions and methods considered in the area, we shall dedicate this talk to the study of certain branes which lie completely inside the singular fibres of the Hitchin fibrations. Through Cayley and Langlands type correspondences, we shall provide a geometric description of these objects, and consider the implications of our methods in the context of representation theory, Langlands duality, and within a more generic study of symmetries on moduli spaces.
- photo, photo, photo, photo, photo

- 12:30-2: Lunch
- 2:00-3:00: Fei Yan (UT Austin),
"Line defect Schur indices, Verlinde algebras and U(1) fixed points"
- Abstract: Given a 4d N=2 superconformal field theory, one could consider Schur index in presence of a half line defect L. Recently Cordova-Gaiotto-Shao found that such index admits an expansion in terms of characters of the chiral algebra introduced by Beem et al. In this talk I will report a puzzling new feature of this expansion: the q → 1 limit of the expansion coefficients is linearly related to the vacuum expectation values < L > in the U(1)_r-invariant vacua of the theory compactified on a circle. This relation can be expressed as a commutative diagram involving three algebras: the OPE algebra of line defects, the algebra of functions on the U(1)_r-invariant vacua, and a Verlinde-like algebra associated to the chiral algebra. This is joint work with Andy Neitzke.
- photo, photo, photo, photo, photo

- 3:15-4:15: Eugene Rabinovich (UC Berkeley),
"A Mathematical Discussion of the Axial Anomaly in the Batalin-Vilkovisky Formalism"
- Abstract: One general perspective on anomalies is that they are a measure of the obstruction to giving the partition function a well-defined value. Using the Batalin-Vilkovisky formalism---as developed by Costello and Gwilliam---we give a mathematical justification of this perspective for the case of perturbative anomalies of the massless free fermion. In particular, for the case of the axial anomaly, we recover the index of the Dirac operator as the relevant obstruction.
- photo, photo, photo, photo, photo, photo, photo, photo

- 10:00-11:00: Daniel Roberts (IAS / FAIR),
"Chaos and the growth of operators"
- 18th meeting: Saturday October 7, 2017, at VT in Blacksburg, VA.
Group photos
here,
here,
here.
Schedule:
- Friday October 6, 2017: Optional informal dinner, starting at 7:15 pm
at
Zeppoli's, at
810 University City Boulevard in Blacksburg.
(Second right from Price's Fork intersection, located just behind the
Verizon store.)
- Saturday October 7, 2017 at VT, in Robeson 210:
- 10:30-11:30: Travis Maxfield (Duke), "A new twist on theories with 8 supercharges,"
video
- Abstract: I will review results from the last few years on novel protected sectors in some theories with 8 supercharges, and I will describe ongoing efforts to extend these results to new theories/new domains.
- photo, photo, photo, photo

- 11:30-1: Lunch
- 1-2: Jennifer Lin (IAS), "Entanglement and spacetime,"
video,
slides
- Abstract: I'll review the evidence, primarily from the Ryu-Takayanagi formula in AdS/CFT, for the idea that spacetime emerges from the entanglement of some underlying quantum system. I’ll then discuss ongoing attempts to understand what the Ryu-Takayanagi formula might be counting from a bulk point of view.
- photo, photo, photo, photo

- 2:10-3:10: Tristan Hubsch (Howard), "Evidence for Infinitely Diverse Non-Convex Mirrors,"
video,
slides
- Abstract: Calabi-Yau hypersurfaces in non-Fano varieties are now a little over two years young, their toric siblings about half of that. Their defining polynomials include rational monomials, and are encoded by non-convex polytopes. Nevertheless, the phases of the corresponding gauged linear sigma models and an increasing number of their classical and quantum characteristics are found to be just as computable. This survey will focus on Batyrev-Hodge numbers, transposition mirror models and discriminants, eying also Yukawa couplings and other results within reach. Showcasing Calabi-Yau hypersurfaces in Hirzebruch n-folds shows this class of constructions to be infinitely vast, with infinite diversity for string theory.
- photo, photo, photo, photo, photo

- 3:20-4:20: Wei Gu (VT), video, slides

- 10:30-11:30: Travis Maxfield (Duke), "A new twist on theories with 8 supercharges,"
video

- Friday October 6, 2017: Optional informal dinner, starting at 7:15 pm
at
Zeppoli's, at
810 University City Boulevard in Blacksburg.
(Second right from Price's Fork intersection, located just behind the
Verizon store.)
- 17th meeting: April 8, 2017, at UNC-CH, in Chapel Hill, NC.
Group photos
here,
here,
here,
here,
here,
here.
Schedule:
- Fri Apr 7: Dinner at Top of the Hill in Chapel Hill, starting at 7:30 pm. This is completely optional, a fun event for those who are in the area. If you want to attend, please inform Eric Sharpe by Wed Apr 5 at 5 pm, so that he can make reservations.
- Sat Apr 8 in Frederick Brooks 141 (faculty conference room), also
accessible from Sitterson Hall,
at UNC-CH:
- 10:30-11:30: Maria Rodriguez (Utah State), ``Blandford-Znajek effect without plasma''
- 11:30-1: Lunch
- 1-2: Tom Rudelius (Harvard), ``6D SCFTs and Group Theory,''
slides
- Abstract: Superconformal field theories in six dimensions (6D SCFTs) have surprising connections to objects in group theory. In this talk, we will explore the relationship between 6D SCFTs, automorphism groups of matrices, and various classes of homomorphisms.
- photo, photo, photo, photo, photo, photo, photo, photo

- 2:10-3:10: Falk Hassler (UNC-CH), ``Surprisingly Complex Punctures from a Dynamical System''
- Abstract: Theories of class S are 4D N=2 SCFTs which result from the compactification of 6D N=(2,0) SCFTs on punctured Riemann surfaces. They provide a geometric perspective on S-duality and are essential in the AGT correspondence. I will present the first step in extending this construction to N=1. To this end, we discuss the punctures relevant in the compactification of the world-volume theory of M5-branes probing an ADE-singularity. They are closely related to the time evolution of a dynamical system and exhibit a surprisingly rich and complex structure compared to N=2.
- photo, photo, photo

- 3:20-4:20: Mboyo Esole
(Northeastern),
``Anomaly free SO(3), SO(5), and SO(6) gauge theories from F Theory''
- Abstract: Orthogonal groups in F Theory are delicate to define as they require a condition on the Mordell-Weil group of the generic elliptic fiber to distinguish them from spin groups. Moreover, the orthogonal groups discussed in the literature are SO(7+k) with k>0. In this talk, I will discuss the explicit construction of lower rank orthogonal groups in F Theory, classify their singular fibers and matter content in 4, 5, and 6 dimensional spacetimes. I will also present the details of their uplift from 5 to 6 dimensions, the cancellations of 6 dimensional anomalies and the structure of the Coulomb phases of the five dimensional theory. All this will be presented as an exercise in intersection theory using a new pushforward theorem for Chow rings of blowups.
- photo, photo, photo, photo, photo, photo, photo, photo, photo

- 16th meeting: November 12-13 2016 at NCSU, in Raleigh, NC, held as the
`Mathematical string theory' special
session at the
fall
southeastern sectional meeting of the AMS.
Schedule:
- Friday November 11:
In lieu of meeting for dinner, I encourage everyone to spend some time
on Friday evening at the
NC Museum of Art, which is open until
9 pm on Friday evenings, and whose main collection is free to visit.
The museum has a small restaurant (the Iris restaurant), as well as a
separate small coffee bar in the west building.
- Saturday November 12 at NCSU, talks in Park Shops room 215:
Update Nov 11
- 7:30am-4pm: Registration (SAS hall lobby)
- 9:00-9:45: Shu-Heng Shao (Institute for Advanced Study), ``Superconformal Indices, BPS Particles, and Chiral Algebras,'' video. (Moved from 8 am) Photos from his talk here, here.
- Jonathan Mboyo Esole: cancelled
- 10:00-10:45: Marco Aldi (VCU), ``Generalized CRF structures and T-duality,'' video (incomplete). Photos from his talk here, here.
- 11:00-3:00: Lunch break and AMS talks
- 3:00-3:45: Michele Del Zotto (Simons Center Stony Brook), ``On Exceptional Instanton Strings,'' video. Photos from his talk here.
- 4:00-4:45: Oscar Chacaltana (IFT Brazil, visiting Johns Hopkins), ``Defects of the 6D (2,0) theories and class-S theories of type E,'' video. Photos from his talk here.

- Sunday November 13 at NCSU, talks in Park Shops room 215:
- 8:00-8:45: He Feng (VT), ``New Evidence for (0,2) Target Space Duality,'' slides, video part 1, video part2. Photos from her talk here, here, here.
- 9:00-9:45: Pavel Putrov (Institute for Advanced Study), ``Exact solutions of N=(0,2) 2d Landau-Ginzburg models,'' slides, video. Photos from his talk here, here, here.
- 10:00-10:45: Savdeep Sethi (Chicago), ``Quantum Rings from Duality,'' video (incomplete). Photos from his talk here.

- Friday November 11:
In lieu of meeting for dinner, I encourage everyone to spend some time
on Friday evening at the
NC Museum of Art, which is open until
9 pm on Friday evenings, and whose main collection is free to visit.
The museum has a small restaurant (the Iris restaurant), as well as a
separate small coffee bar in the west building.

- 15th meeting: Saturday April 23, 2016. Group photos
here,
here,
here.
Schedule:
- Friday April 22: Informal dinner, starting at 7 pm at
Zeppoli's, at
810 University City Boulevard in Blacksburg.
(Second right from Price's Fork intersection, located just behind the
Verizon store.)
- Saturday April 23 at VT, in Robeson 210:
- 9:30 - 10:30: Paul Oehlmann (Bonn, VT), ``Mordell-Weil Torsion in the Mirror of Multi-Sections,'' video, slides. Photos from his talk here, here, here, here, here.
- 10:40 - 11:40: Ilarion Melnikov (JMU), ``Relevant deformations and c-extremization,'' video.
- 11:40-1:15: Lunch. Options include Macado's (922 University City Blvd, B-burg) and India Garden Restaurant (210 Prices Fork Road, B-burg).
- 1:15-2:15: Taizan Watari (IPMU, Harvard), ``Heterotic--Type IIA dualtiy and degeneration of K3 surface,'' video, slides.
- 2:30-3:30: Louise Dolan
(UNC-CH),
``General Solution of The Scattering Equations,''
video.
- Abstract: The scattering equations, originally introduced by Fairlie and Roberts in 1972 and more recently shown by Cachazo, He and Yuan to provide a kinematic basis for describing tree amplitudes for massless particles in arbitrary space-time dimension, have been reformulated in polynomial form. The scattering equations for $N$ particles are equivalent to $N-3$ polynomial equations $h_m=0$, $1\leq m\leq N-3$, in $N-3$ variables, where $h_m$ has degree $m$ and is linear in the individual variables. Facilitated by this linearity, elimination theory is used to construct a single variable polynomial equations of degree $(N-3)!$ determining the solutions.
- Photos from her talk here, here, here, here, here.

- Friday April 22: Informal dinner, starting at 7 pm at
Zeppoli's, at
810 University City Boulevard in Blacksburg.
(Second right from Price's Fork intersection, located just behind the
Verizon store.)

- 14th meeting: Saturday October 24, 2015.
Group photo here.
Schedule:
- Friday October 23: Informal dinner, starting at 7:30 pm at
Sitar Indian Cuisine,
at 3630 Durham Chapel Hill Blvd in Durham NC.
- Saturday October 24 at Duke, in physics room 130:
- 9:30-10:30: Cyril Closset (Stony Brook),
``Localization on twisted spheres in two-dimensional gauge theories''
(slides,
video)
- Abstract: I will revisit the A-twisted gauged linear sigma model (GLSM) in the case of (2,2) supersymmetry in two dimensions, together with its Omega-background deformation. Exact results for correlation functions can be obtained in terms of residues on the Coulomb branch, which has a number of interesting applications. I will also consider the generalization to (0,2) supersymmetric GLSM.

- 10:40-11:40: Abhijit Gadde (IAS), ``Aspects of 2d (0,2) theories'' (slides, video)
- 11:40-1: Lunch
- 1-2: Chen Sun (VT), ``Rethinking gauge theory through Connes' noncommutative geometry'' (slides, video)
- 2:10-3:10: Daniel Park (Stony Brook, Rutgers),
``Towards finding all string vacua
in six dimensions''
(video)
- Abstract: I will review the efforts made towards approaching string universality in six dimensions and report recent "cartographic" developments on exploring the landscape of six-dimensional string vacua. A working conjecture is that all the six-dimensional string vacua can be constructed in F-theory, which leads to the problem of classifying all elliptically fibered Calabi-Yau threefolds. I will present some progress on classifying all the four-manifolds that can be used as a base of such threefolds.

- 3:20-4:20: Xin Gao (VT), ``Generalized Complete Intersection Calabi-Yau
(gCICY) Manifold and Its
Physical Applications''
(slides)
- Abstract: We present a generalization of the complete intersection in products of projective space (CICY) construction of Calabi-Yau manifolds. Their utility stems from the fact that they can be simply described in terms of a `configuration matrix', a matrix of integers from which many of the details of the geometries can be easily extracted. The generalization we present is to allow negative integers in the configuration matrices which were previously taken to have positive semi-definite entries. This broadening of the complete intersection construction leads to a larger class of Calabi-Yau manifolds than that considered in previous work. These new Calabi-Yau manifolds are complete intersections in (not necessarily Fano) ambient spaces with an effective anticanonical class. We find examples with topology distinct from any that has appeared in the literature to date. The new manifolds thus obtained have many interesting features. For example, we explore contributions to the superpotential and the structure of instantons wrapping effective divisors in Calabi-Yau fourfolds.

- 9:30-10:30: Cyril Closset (Stony Brook),
``Localization on twisted spheres in two-dimensional gauge theories''
(slides,
video)

- Friday October 23: Informal dinner, starting at 7:30 pm at
Sitar Indian Cuisine,
at 3630 Durham Chapel Hill Blvd in Durham NC.

- 13th meeting: Saturday April 11, 2015. Schedule:
- Friday April 10: Informal dinner tentatively at
The Pit (321 W. Geer St.) in
Durham, starting at 7 pm.
The Pit is located at the intersection of Geer St and Rigsbee Avenue, beside Fullsteam Brewery and across the street from Motorco Music Hall. There is a parking lot across the street also; however, access to the lot is from Geer St. There is also parking available in smaller lots elsewhere in the area, plus -- if you're willing to walk a bit -- there is a large lot at the 400 block of Morris St.

- Saturday April 11:
- 9:30-10:30: Philip Argyres (University of Cincinnati), ``Geometric constraints on the space of N=2 SCFTs'' (slides, video)
- 10:40-11:40: Sheldon Katz (University of Illinois), ``Topological string partition function on elliptically fibered Calabi-Yau threefolds and Jacobi forms''
- 11:40-1: Lunch
- 1-2: Diana Vaman (University of Virginia), ``Entanglement Hamiltonians for chiral fermions'' (slides)
- 2:10-3:10: Seung-Joo Lee (VT), ``BPS states, quiver invariants and mutations'' (slides)
- 3:20-4:20: Jirui Guo (VT), ``Triality of two-dimensional (0,2) theories'' (slides)

- Friday April 10: Informal dinner tentatively at
The Pit (321 W. Geer St.) in
Durham, starting at 7 pm.

- 12th meeting: Saturday October 25, 2014. Schedule:
- Friday October 24: informal dinner, meet at 6:30 pm at Dales Indian Cuisine, 811 North Ninth St, Durham. Parking is available in the gravel lot across the street from the restaurant.
- Saturday October 25 at Duke, in physics room 119:
- 10:15 - 11:15: Chris Beasley (Northeastern University),
``Self-Linking for Legendrian Knots''
- Abstract: I will discuss a new class of supersymmetric Wilson loop operators in pure N=2 Yang-Mills-Chern-Simons theory. These Wilson loops preserve one supercharge on-shell and wrap arbitrary Legendrian knots in the standard contact R^3. Conjecturally, perturbation theory produces a series of finite-type Legendrian invariants for the knot. These invariants can be analyzed by means of a new "perturbative" localization principle, which I illustrate at leading-order. This talk is based upon joint work with Brendan McLellan and Ruoran Zhang.

- 11:30-1: Lunch
- 1-2: Anindya Dey (UT Austin), ``Field Theory on Gibbons-Hawking Spaces''
- Abstract: The IR Lagrangian of an N=2 supersymmetric gauge theory compactified on R^3 x S^1, around a generic point of its moduli space, is a 3d sigma model with a hyperkahler target space. We consider a related problem of constructing the IR Lagrangian of an N=2 theory on a special family of circle fibrations over R^3 -- namely Gibbons-Hawking spaces. We propose that the answer is a novel deformation of the standard 3d hyperkahler sigma model and study the constraints imposed by supersymmetry on such a theory. In particular, supersymmetry implies that the contribution of the NUT center to the sigma model path integral must be a holomorphic section of a certain holomorphic line bundle over the hyperkahler target space. We illustrate various features of this deformed sigma model using certain examples involving Abelian gauge theories on Gibbons-Hawking spaces.

- 2:15-3:15: Chris Beem (IAS), ``Chiral symmetry algebras and superconformal field theories in four and six dimensions''
- Abstract: I will describe the identification of a supersymmetry-protected subalgebra of the operator algebra of any four-dimensional N=2 SCFT or six-dimensional (2,0) SCFT that takes the form of a two-dimensional chiral algebra. The structure of this protected chiral algebra reflects the physics of the parent four- or six-dimensional theory in interesting ways. In many cases the relevant chiral algebra can be given an economical description as a W-algebra. Applications of this structure include the derivation of new unitarity bounds for four-dimensional SCFTs with global symmetries and the computation of three-point functions of half-BPS operators in the (2,0) theories at finite central charge.

- 3:30-4:30: Falk Hassler (Munich),
``String Geometry Beyond the Torus,''
slides here
- Abstract: Besides propagating in target space like a point particle, a closed string is also able to wind around non-contractible circles. A direct consequence thereof is T-duality. In the textbook example, it identifies the closed string dynamics on a large and a small circle by interchanging its winding and momentum modes. Patching a background by such dualities clearly goes beyond the notion of conventional geometry. However, there are extensive efforts to embed them into a framework called string geometry. It provides access to a vast number of new backgrounds with intriguing phenomenology, like e.g. the possibility to obtain de Sitter vacua. Double Field Theory (DFT) is the most promising approach to describe these backgrounds and their properties. But still, it is closely related to the torus. I will present a theory based on Closed String Field theory starting from a Wess-Zumino-Witten model which goes beyond the torus. It plays an important role in clarifying the recent confusion about different constraints in DFT. Furthermore it allows to uplift a large class of new backgrounds to string theory. These backgrounds are not T-dual to any geometric ones.

- 10:15 - 11:15: Chris Beasley (Northeastern University),
``Self-Linking for Legendrian Knots''

- 11th meeting: Fri-Sat April 4-5, joint UNC/Duke meeting following the
theme 'Mathieu moonshine'. Schedule:
- Thursday April 3: informal get-together around 6 pm in the evening at Hickory Tavern, beside lobby of Hampton Inn (370 East Main, Carrboro, just a few blocks from the physics dep't). People interested are welcome to join an informal dinner party.
- Friday April 4 at UNC: (see map)
- 9-10: snacks, outside Chapman 201
- 10-11 (Chapman 201): Daniel Persson (Sweden), ``Second quantization of Mathieu moonshine''
- 11-noon (Chapman 201): Daniel Whalen (Stanford), ``Vector-valued automorphic integrals''
- noon-1:45: lunch
- 1:45-2:45 (Chapman 201): Timm Wrase (Stanford), ``Mathieu moonshine and heterotic string compactifications''
- 2:45-4: break, possibly including tour of UNC campus's NC history museum
- 4-5: discussion in Chapman 125
- 6:30: dinner at Crook's Corner in Chapel Hill.

- Saturday April 5 at Duke:
- 10:15-11:15 (physics 119): Lara Anderson (VT), ``Geometric constraints in heterotic/F-theory duality''
- 11:30-1: lunch
- 1-2 (physics 119): Xi Dong (Stanford), ``String theory avatars of Conway and Mathieu symmetries''
- 2:15-3:15 (physics 119): Christoph Keller (Rutgers), ``Partition functions and Poincare series''
- 3:30-4:30 (physics 119): Ben Gaines (Duke), ``(0,2) deformations and the Hilbert scheme''

- 10th meeting: Friday October 11, 2013, in Gross Hall 330.
Schedule:
- 10:15-11:15: Sergei Gukov (Caltech), ``Fivebranes and 4-manifolds''
- 1-2: Eirik Svanes (Oxford), ``Heterotic supergravity, SU(3) structures, and the alpha' expansion''
- 2:15-3:15: Emanuel Scheidegger (Freiburg, Harvard), ``Topological strings and quasimodular forms''
- 3:30-4:30: Mauricio Romo (IPMU), ``Exact results in two-dimensional (2,2) supersymmetric gauge theories with boundary''

- 9th meeting: Saturday April 6, 2013, in Duke physics room 119.
Schedule:
- 10-11: Daniel Park (Stony Brook)
- 11:05-11:30: Bei Jia (VT)
- 1-2: Paul Aspinwall (Duke)
- 2:15-3:15: Nils Carqueville (Stony Brook)
- 3:30-4:30: Katrin Wendland (Freiburg)

- 8th meeting: Friday-Saturday September 28-29, 2012. Schedule:

Friday:- 10-11: Matt Ballard (Wisconsin) (Hudson Hall 218)
- noon-1: Nick Addington (Duke) (physics faculty lounge)

- 10:30-11:30: Callum Quigley (Chicago)
- 1-2: Marco Bertolini (Duke)
- 2:30-3:30: Djordje Minic (VT)

- 7th meeting: Saturday March 24, 2012, in the physics faculty lounge
(room 298).
Schedule:
- 10:30-11:30: Jacques Distler (Texas-Austin)
- 1-2: Ilarion Melnikov (Potsdam, AEI), ``Adventures in quantum restriction''
- 2:30-3:30: Katrin Becker (Texas A&M), ``D-brane and O-plane actions from string amplitudes,'' update: replaced by Daniel Robbins (Texas A&M)

- 6th meeting: Saturday October 8, 2011, in the physics first floor
classroom. Schedule:
- 10:30-11:30: Josh Lapan (Perimeter), ``Beyond CICY's through non-abelian GLSMs''
- 1:15-1:45: Bei Jia (VT), ``Rigidly supersymmetric gauge theories on curved superspace''
- 2-3: Philip Szepieowski (UVA), ``Consistent truncations of IIB on Sasaki-Einstein manifolds and N-2 supergravity in five dimensions''
- 3:15-4:15: Harry Thacker (UVA), ``The role of the RR U(1) guage field in holographic QCD''

- 5th meeting: Saturday April 2, 2011, in physics room 119.
Schedule:
- 10:30-11:30: Paul Aspinwall (Duke), ``New results from the ancient standard embedding''
- 1-2: Eric Sharpe (VT), ``Quantization of FI parameters in supergravity''
- 2:30-3:30: Djordje Minic (VT), ``String theory and non-equilibrium physics''

- 4th meeting: Saturday October 16, 2010, in physics 298 (faculty lounge).
Schedule:
- 10:30-11:30: Lara Anderson (U-Penn), ``Supersymmetry and moduli stabilization in heterotic theories''
- 1-2: Ronen Plesser (Duke)
- 2:30-3:30: Chaolun Wu (UVA), ``Relativistic and non-relativistic real-time finite-temperature AdS/CFT''

- 3rd meeting: Friday April 2, 2010, in physics 298 (faculty lounge).
Schedule:
- 10-11: Paul Aspinwall (Duke), ``Quivers and matrix factorizations''
- 11:15-12:15: Ronen Plesse (Duke)
- 2-3: Usama al-Binni (Tennessee), ``Hawking radiation and quasinormal modes for a black hole on a tensional codimension-2 brane''
- 3:20-4:20: Thomas Creutzig (UNC-CH)

- 2nd meeting: Friday October 2, 2009. Schedule:
- 10:15-11:15: James Alsup (Tennessee), ``Gravitational duals to time-dependent hydrodynamics'' (LSRC A156)
- 1-2: Diana Vaman (UVA), ``All 4-dimensional static, spherically symmetric, 2-charge abelian Kaluza-Klein black holes and their CFT duals'' (physics 298)
- 3:15-4:15: Stefano Guerra (Duke), ``The Catanese conjecture for flag varieties'' (physics 298)

- 1st meeting: Friday April 3, 2009, in LSRC A156. Schedule:
- 10:15-11:45: Paul Aspinwall (Duke), ``Geometry with zero-brane probes''
- 1:15-2:45: Lev Rozansky (UNC-CH)
- 2:45-4:15: Djordje Minic (VT), ``The physics of the Riemann zeros''