mathematical string theory meeting

This is the webpage for the southeastern regional mathematical string theory meeting, held every six months (early April and early October), often at Duke University but occasionally elsewhere.

Speakers tentatively include Robert Bryant (Duke), Changha Choi (Perimeter Institute), Theodore Jacobson (UCLA), Diana Vaman (UVA), Mendel Nguyen (NCSU).

Tentative schedule:

- Friday September 22: Optional informal dinner, starting at 7 pm,
at the Raleigh Times,
located at 14 E. Hargett St in downtown Raleigh, NC.
See e.g. here
for parking locations in downtown. If you want to join us, please RSVP
Eric Sharpe by Thurs Sept 21 at noon, so that he can make a suitable
reservation.
- Saturday September 23: All talks will be held in Riddick Hall,
room 314.
- 10:00 - 11:00: Robert Bryant (Duke), "The G_2 Laplacian flow"
- Abstract: 7-manifolds with holonomy G_2 are important as background for M-theory, and understanding the compact solutions, possibly with singularities, is a significant goal of the subject. The G_2-Laplacian flow is the G_2-analog of the Kahler-Ricci flow for Calabi-Yau metrics in complex geometry. In this talk, I’ll give an introduction to the subject and describe the current state of knowledge, in particular some of the results and problems related to the study of solitons of the flow.
- Photos here, here, here, here, here, here

- 11:15 - 12:15: Changha Choi (Perimeter), "Deconfinement in three dimensional gauge theories"
- Abstract: One of the most important characterizations in gauge theory is the nature of confinement. What makes 3d gauge theory particularly captivating is its tendency to exhibit robust deconfinement in various scenarios. We elucidate how this phenomenon can sometimes be comprehended exclusively through the lens of symmetries and anomalies. Furthermore, to shed more light on the dynamics at play, we delve into the minimal supersymmetric Yang-Mills-Chern-Simons theory and initiate the semiclassical analysis by placing it on the small circle.
- Photos here, here, here

- 12:30 - 2:00: Lunch
- 2:00 - 3:00: Diana Vaman (UVA),
"Tree-level Graviton Scattering in the Worldline Formalism"
- Abstract: We use the worldline formalism to study tree-level scattering processes involving gravitons. A massless spin 2 particle is described by an N=4supersymmetric worldline action which is also O(4) symmetric. More generally, N=2S supersymmetric worldline actions exhibiting O(N) symmetry describe free spin S particles. Recently a BRST approach was used to construct the on-shell background graviton emission vertex from a graviton worldline. Nonetheless, an action describing the coupling of higher spin (S≥2) particles with generic background gravity is unknown. In this paper, we found that in order to reproduce Einstein's general relativity 3-point graviton vertex, interpreted as the emission of an off-shell graviton from the worldline, the coupling to background gravity must break the O(4) symmetry to O(2)×O(2). In addition to this symmetry-breaking feature, we also found that the coefficient β of the worldline action counterterm βR differs from previous results in the literature. By comparing the linearized graviton and photon emission vertex operators from different worldlines, we noticed that they obey a squaring relation. For MHV (Maximal Helicity Violating) amplitudes, these squaring relations among the linearized vertex operators directly result in double-copy-like relations between the scattering amplitudes.
- Unfortunately, Diana had to cancel, but she did send her slides.
- slides

- 3:15 - 4:15: Theodore Jacobson (UCLA),
"Emergent 1-form symmetries and confinement"
- Abstract: We discuss the conditions under which higher-form symmetries can emerge in various limits. Such symmetries can appear as one tunes microscopic parameters, such as the masses of charged particles, or in the long-distance limit of a fixed quantum field theory. In the latter case, a minimal requirement for a 1-form symmetry to emerge is that the would-be symmetry generators behave topologically at long distances, and that they have non-trivial correlation functions. These conditions are met when the would-be symmetry is spontaneously broken or involved in 't Hooft anomalies, in which case the emergent symmetries have dramatic effects on the ground state structure. We comment on the lack of emergent 1-form symmetry in the 't Hooft large N limit of QCD with fundamental quarks, as well as in the long-distance limit of QCD at fixed finite N with heavy quarks.
- slides
- Photos here, here

- 4:30 - 5:30: Mendel Nguyen (NCSU)

- 10:00 - 11:00: Robert Bryant (Duke), "The G_2 Laplacian flow"

If you are an individual with a disability and desire an accommodation, please contact Eric Sharpe at least 10 business days prior to the event.

- For those flying in, the closest airport is Raleigh-Durham International (RDU).
**NCSU:**- Maps of NCSU's campus can be found here.

IMPORTANT: If you wish to be reimbursed, see here for the paperwork you will need to provide, and also let Eric Sharpe know that you will wish to be reimbursed.

- NC Museum of Art in Raleigh, open late on Friday evenings,
- NC Museum of Natural Sciences,
- NC Museum of History
- Theatre in the park in Pullen Park beside the NCSU campus
- Carolina Ballet
- NC Opera
- 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,
- A list of other Raleigh events is here.