Southeastern regional
mathematical string theory meeting

Next meeting:

Speakers tentatively include Mithat Unsal (NCSU), Daniel Robbins (University at Albany), Patrick Jefferson (MIT), Callum Brodie (VT), and James Wheeler (Duke).

We will try to broadcast the meeting on zoom. If you want to watch the talks remotely, email Eric Sharpe for the zoom coordinates.

Tentative schedule:

• Friday Oct 7: Informal dinner at Sitar Indian Cuisine, at 3630 Durham Chapel Hill Blvd in Durham. If you wish to join us, aim to be there by 7:45 - 8 pm, and please let Eric Sharpe know by Thursday Oct 6 around lunchtime, so that he can make a reservation.

• Saturday Oct 8: (All talks will be at Duke University, physics building room 119. Although the talks will be in-person, we will also attempt to broadcast on zoom, details to appear later.)

  • 10:00-11:00: Mithat Unsal (NCSU), "Adiabatic continuity, anomaly preserving compactifications, and calculable confinement"
    • Abstract: I will describe the idea of adiabatic continuity which can be used to continuously connect strongly coupled gauge theories on R^4 to compactified gauge theories on R^2 x T^2 by using 't Hooft flux background. In this process, I will describe how to perform semi-classical fractional instanton analysis in the 't Hooft flux background in a general class of theories. In the weak coupling (small T^2) regime, properties such as confinement, chiral symmetry breaking, and multi-branch structure as a function of theta angle are semi-classically calculable. As opposed to common beliefs emanating from the 70s, which emphasize that these are necessarily strong coupling phenomena, all of them can be realized in weak coupling regime. I will mention the roles of fractional instantons, resurgence, and TQFT couplings, and state some open problems.

  • 11:15-12:15: Daniel Robbins (University of Albany), "Topological defects and decomposition"
    • Abstract: Decomposition is the idea that a d-dimensional quantum field theory with a global (d-1)-form symmetry is equivalent to a disjoint union of quantum field theories. A rich source of examples comes from 2D orbifolds in which a subgroup of the orbifold group acts trivially on local operators. I will review that story using the language of topological defect operators and discuss the role of discrete torsion and anomalies. I will also briefly discuss theories in higher dimensions, and how decomposition plays a role in the fusion of condensation defects.

  • 12:30-2:00: Lunch

  • 2:00-3:00: Patrick Jefferson (MIT), "Euclidean D3 instantons and O3 planes in 4D F-theory vacua"
    • Abstract: In F-theory, O3 planes are understood to correspond to terminal Z2 singularities in the compactification space that do not admit crepant resolutions and are hence difficult to analyze using classical tools in complex and algebraic geometry. I will describe a conjectural algorithm for analyzing the Hodge diamonds and intermediate Jacobians of vertical divisors of elliptic Calabi-Yau fourfolds in the presence of terminal Z2 singularities. This algorithm, which circumvents many of the computational difficulties introduced by these singularities, has immediate applications for analyzing the contributions of Euclidean M5 instantons to the superpotential of 4D F-theory compactifications in the ​Sen limit. Based on forthcoming work with Manki Kim (MIT).

  • 3:15-4:15: Callum Brodie (VT), "Target Space Duality from Gauge-Gravity Pair Creation"
    • Abstract: Unlike for Type II string theory, it is currently not known whether it is possible for compactifications of the heterotic string to pass through a topological transition. This is due to the added complication of a background gauge bundle, whose consistent path across a topological transition has so far eluded understanding. Separately, there has been the observation from the rich structure of GLSMs, of the phenomenon of 'target space duality', in which heterotic compactification on two topologically distinct geometries, carrying different gauge bundle backgrounds, can apparently give rise to the same external physics. In this talk, I will provide a novel consistent description for how the background heterotic gauge bundle can traverse a topological transition, and show that this process precisely connects pairs of target space dual theories.

  • 4:30-5:30: James Wheeler (Duke), "A Dual Approach to Defining Black Holes"
    • Abstract: I would like to discuss a novel approach to defining black holes in classical General Relativity in a manner that demands no constrictive structure of the spacetime. In particular, we will not require asymptotic flatness or any other such global hypotheses, save standard causality conditions. Even so, the subset we identify as the black hole has a natural global structure and is designed to optimally reflect intuitive physical notions as to what the term should mean with respect to the causal structure of spacetime at large. The approach outlines a program which may be rigorously carried through in a number of ways (similar to how there are various ways to technically realize the standard 'complement of the past of future infinity'), of which we will emphasize one as being most natural.

Discrimination / diversity:

Coffee:

• There are two coffee shops in the Bryan Center.
• Another coffee shop, ``Twinnies,'' is located in the Fitzpatrick Center.
• Coffee is served in the LSRC cafeteria.
• There is a coffee shop in the Perkins Library.

• Caribou Coffee, 110 West Franklin Street
• Starbucks, 103 East Franklin Street
• Alpine Bagel Cafe, in the Carolina Union

For visitors to the area:

• For those flying in, the closest airport is Raleigh-Durham International (RDU).
• Duke:
• A map of Duke's campus can be found here.
• We have parking passes for the lot beside the physics department building, email Eric Sharpe for such a pass if you will drive in.
• If you don't have a pass, convenient visitor parking at Duke can often (though not always) be found in the parking deck behind the Bryan Center, off of Science Drive. On rare occasion, that parking deck may be closed or full. In such an event, there is a visitor information center located at the traffic circle on Towerview Road, and the staff there can provide other visitor parking options. (For example, there is a parking deck on Erwin Road, across from the main entrance to the hospital -- but getting from there to the physics department is nontrivial.) Alternatively, see here for a comprehensive list of Duke visitor parking options.
• For those driving in from out of town, it should be noted that I-40 typically gets jammed with RTP traffic during morning and afternoon rush hours.
• UNC-CH:
• A map of UNC-CH's campus can be found here.
• For parking in Chapel Hill, there are several municipal parking lots and decks off of Rosemary St., parallel and next to Franklin St., see here or find a map here.

Funding:

Previous regional meetings:

Other upcoming meetings of interest:

Raleigh-Durham area attractions:

• Overview of Durham attractions
• Morehead Planetarium in Chapel Hill,
• There is a small Museum of NC history on the UNC-CH campus.
• Nasher Museum of Art at Duke University, open late on Thursday evenings,
• NC Museum of Art in Raleigh, open late on Friday evenings,
• NC Museum of Natural Sciences, which has movies on the evening of the last Friday of each month,
• NC Museum of History
• Reader's Corner, a used book store on Hillsborough St. in Raleigh,
• Nice Price Books, another used book store on Hillsborough St. in Raleigh,
• Other Raleigh events held on the first Friday of every month are listed here,
• Full Frame Documentary Film Festival, held in April of each year.
• Events in Chapel Hill are often listed here.