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 Ibrahima Bah (Johns Hopkins), Naomi Gendler (Cornell), Max Hubner (U Penn), Tristan Hubsch (Howard), Yichul Choi (Stony Brook).

Tentative schedule:

- Friday Apr 7: Optional informal dinner at
Zeppoli's at 810 University City Boulevard in Blacksburg, at 7:30 pm.
- Saturday Apr 8: All talks will be held in Robeson Hall, room 210.
Group photo
here and
here.
Schedule below:
- 10:00 - 11:00: Ibrahima Bah (Johns Hopkins),
"Non-invertible symmetry, holography and branes"
- Abstract: In this talk I will discuss some general methods for realizing topological symmetry generators in holography. In particular I will present a specific realization of non-invertible symmetry generators and their fusion rules in holographic duals of SU(N)/Z_N N=1 SYM. This will be both from a bottom-up perspective from an effective theory in AdS5, and from a top-down perspective in terms of D-branes in AdS5 backgrounds.

- 11:15 - 12:15: Tristan Hubsch (Howard),
"Generalized Mirror Models Beyond Algebraic Toric Spaces"
- Abstract: Calabi-Yau hypersurfaces in toric (complex algebraic) varieties and their mirror models are well understood, including the gauged linear sigma model (GLSM) and other stringy corrections to their cohomology ring structures. That however is but the tip of the iceberg. Non-convex, flip-folded and multi-winding (but "regularly subdivisible") variants of polytopes and fans encode U(1)^n-equivariant (co)homology on smooth manifolds with GLSM U(1)^n-action that are generically not algebraic, but have well-defined Calabi-Yau hypersurfaces. Surprisingly, at least some of these generalizations already turned up within deformation families of otherwise well understood algebraic constructions.
- audio
- Slides: pdf, key

- 12:30 - 2:00: Lunch
- 2:00 - 3:00: Naomi Gendler (Cornell),
"The Visible Axiverse"
- Abstract: In this talk, I will review the construction of an ensemble of axion models arising from type IIB string theory on toric hypersurface Calabi-Yau threefold orientifolds. I’ll first recount the absence of a Peccei-Quinn quality problem in this landscape of theories, and then explain some of the observational constraints on these string theory axions, coming from dark matter bounds as well as axion-photon coupling experiments. Finally, I’ll explain a mechanism that suppresses axion-photon couplings compared to naive estimates, and present some preliminary data on these couplings.
- video

- 3:15 - 4:15: Yichul Choi (Stony Brook),
"Noninvertible Gauss Law and Axions"
- Abstract: In the past years, the notion of global symmetry in quantum field theory has gone through a rapid evolution to include generalized symmetries generated by topological defects of higher codimensions and/or with noninvertible fusion algebras. A prototypical example of a generalized global symmetry is the electric 1-form symmetry in free Maxwell theory. An electric 1-form symmetry is a modern, symmetry-based way to describe the Gauss law. In this talk, we will consider axion-Maxwell theory, where the presence of the axion-photon coupling explicitly breaks the naïve electric 1-form symmetry, hence making the Gauss law anomalous. We will see that, however, the electric 1-form symmetry can be resurrected if we give up invertibility. The noninvertible electric 1-form symmetry leads to a modified version of the Gauss law, which we call the noninvertible Gauss law.
- slides
- video (Note: audio doesn't begin until 2/3 through.)

- 4:30 - 5:30: Max Hubner (Univ Pennsylvania),
"The Branes Behind Generalized Symmetry Operators"
- Abstract: We discuss a new place to wrap branes. Given a QFT geometrically engineered in String/M-theory branes can be wrapped on asymptotic cycles of the internal space at metric infinity. Whenever the asymptotic cycles are formally of infinite volume the space-time dimensions of the wrapped branes support at best a topological field theory. Further, such `branes at infinity' are at infinite distance from the localized QFT and therefore interact with it only topologically. Overall, such wrappings construct topological operators in the QFT which we argue to generate generalized global symmetries. We give examples in well-known theories.
- video
- slides

- 10:00 - 11:00: Ibrahima Bah (Johns Hopkins),
"Non-invertible symmetry, holography and branes"

- For those flying in, the closest airport is Roanoke-Blacksburg Regional Airport (ROA).
**VT:**- Maps of VT's campus can be found here.
- Nearby hotels include, for example,
- On weekends (between Fri 5 pm and Mon 7 am), parking is free in any regular lot, unless otherwise marked.
- A map with Robeson Hall, local hotels, and coffee shops marked explicitly is 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.

In addition, June 2-4 2023 will be the
Richmond geometry festival,
at Virginia Commonwealth University,
which has some string and string-adjacent talks.

- Taubman Museum of Art
- Center in the Square
- Virginia Museum of Transportation
- Link Museum
- Historic Smithfield Plantation
- Chateau Morrisette Winery and Restaurant
- Cascades Recreation Area
- Peaks of Otter
- Blue Ridge Parkway
- Dragon's Tooth Trail
- Natural Bridge
- American Shakespeare Center