During the 2022-23 academic year, the CMSA will host a seminar on Swampland, organized by Max Wiesner and Cumrun Vafa. This seminar will take place biweekly on Mondays at 11:00 am - 12:00 pm (Boston time). The meetings will take place in Room G10 at the CMSA, 20 Garden Street, Cambridge MA 02138 and virtually via Zoom. To learn how to attend, please subscribe here. Talks will be posted on the Swampland Seminars YouTube channel. The schedule will be updated as talks are confirmed.  

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  • April 24, 2023 11:00 AM
Speaker: Thomas Grimm
Title: The Tameness of Quantum Field Theories 
Venue: Jefferson 368

Swampland Seminar Speaker: Thomas Grimm (Utrecht U.) Title: The Tameness of Quantum Field Theories Abstract: Tameness is a generalized notion of finiteness that is restricting the geometric complexity of sets and functions. The underlying mathematical foundation lies in tame geometry, which is built from o-minimal structures introduced in mathematical logic. In this talk I formalize the connection between quantum field theories and logical structures and argue that the tameness of a quantum field theory relies on its UV definition. I quantify our expectations on the tameness of effective theories that can be coupled to quantum gravity and on CFTs. In particular, I present tameness conjectures about CFT observables and propose universal constraints that render spaces of CFTs to be tame sets. I then highlight the relation of these conjectures to other swampland conjectures, e.g., by arguing that the tameness…

  • April 10, 2023 11:00 AM
Speaker: Seung-Joo Lee (IBS Daejeon)
Title: Swampland bounds on the abelian gauge sectors
Venue: CMSA Room G10

Swampland Seminar Speaker: Seung-Joo Lee (IBS Daejeon) Title: Swampland bounds on the abelian gauge sectors Abstract: In this talk we will derive various bounds on the 0-form and the 1-form abelian gauge sectors of gravitational effective theories in 6 dimensions with minimal supersymmetry. We will start by considering 6-dimensional F-theory vacua with at least one tensor multiplets, to bound for them the number of the (0-form) U(1) gauge factors as well as the cyclic orders of the 1-form discrete gauge factors. While the two abelian gauge sectors may look rather independent, we will observe that both are heavily constrained by the solitonic heterotic strings present in the spectrum, which provide a common intuition for the derived bounds. Building upon…

  • March 27, 2023 11:00 AM
Speaker: Valerio De Luca
Title: Recent developments on the tidal Love numbers of black holes
Venue: CMSA Room G10

Swampland Seminar Speaker: Valerio De Luca (UPenn) Title: Recent developments on the tidal Love numbers of black holes Abstract: Tidal Love numbers describe the deformability of compact objects under the presence of external tidal perturbations, and are found to be exactly zero for black holes in pure General Relativity. This property is however fragile, since they receive corrections from higher-order derivative terms in the theory. We show that the tidal deformability of neutral black holes is constrained by the Weak Gravity Conjecture.

  • March 13, 2023 11:00 AM
Speaker: David Andriot
Title: String theory scalar potentials and their critical points
Venue: CMSA Room G10

Swampland Seminar Speaker: David Andriot (Annecy, LAPTH) Title: String theory scalar potentials and their critical points Abstract: Positive scalar potentials in string effective theories could provide an origin to Dark Energy, responsible for the accelerated expansion of our universe today or during inflation. It is thus crucial to characterize these scalar potentials, namely their slope, their critical points (de Sitter solutions) and the associated stability, as also advocated by the Swampland Program. We will present such characterizations. Going further, we will also discuss negative scalar potentials, and make related observations on anti-de Sitter solutions, in particular on a new mass bound, as well as comments on scale separation.

  • February 13, 2023 11:00 AM
Title: Parity and Cobordism
Venue: CMSA Room G10

Swampland Seminar Speaker: Jake McNamara (Caltech) Title: Parity and Cobordism Abstract: The swampland cobordism conjecture provides a convenient way to discuss conserved charges associated with the topology of spacetime. However, much of the power of the cobordism conjecture comes from a mathematical black box: the Adams spectral sequence. In this talk, I will give physical meaning to this black box through a concrete example: domain walls arising from the spontaneously breaking of parity symmetry, which arise in particle physics in Nelson-Barr models. I will argue that parity domain walls are exactly stable, and interpret this stability as the result of an unusual type of gauge symmetry that can only occur in gravitational theories.  

  • January 30, 2023 11:00 AM
Speaker: Ignatios Antoniadis
Title: Swampland program, extra dimensions and supersymmetry breaking
Venue: CMSA Room G10

Swampland Seminar Speaker: Ignatios Antoniadis (LPTHE Paris) Title: Swampland program, extra dimensions and supersymmetry breaking Abstract: I will argue on the possibility that the smallness of some physical parameters signal a universe corresponding to a large distance corner in the string landscape of vacua. Such parameters can be the scales of dark energy and supersymmetry breaking, leading to a generalisation of the dark dimension proposal. I will discuss the theoretical framework and some of its main physical implications to particle physics and cosmology.

  • December 05, 2022 11:00 AM
Speaker: Markus Dierigl
Title: IIB Explored – Dualities, Bordisms, and the Swampland
Venue: Jefferson 356

Swampland Seminar Location: Jefferson Physical Laboratory, Seminar room J356 Speaker: Markus Dierigl (LMU Munich) Title: IIB Explored – Dualities, Bordisms, and the Swampland Abstract: In this talk I will discuss the application of the Cobordism Conjecture to type IIB supergravity with non-trivial duality bundle. Calculating the relevant bordism groups we find that they are highly non-trivial and would predict the presence of various global symmetries in the underlying theory. Since quantum gravity theories do not allow for global symmetries, we discuss which defects need to be included to break them completely. Interestingly, we find many backgrounds that are well-known in the F-theory literature, such as [p,q]-7-branes, non-Higgsable clusters, as well as S-folds and their generalizations to higher codimensions. Further including…

  • November 15, 2022 11:00 AM
Speaker: Alvaro Herraez
Title: The Emergence Proposal in Quantum Gravity and the Species Scale
Venue: CMSA Room G10

Swampland Seminar Speaker: Alvaro Herraez (Saclay) Title: The Emergence Proposal in Quantum Gravity and the Species Scale Abstract: The Emergence Proposal claims that in Quantum Gravity the kinetic terms of the fields in the IR emerge from integrating out (infinite) towers of particles up to the QG cutoff. After introducing this proposal in the context of the Swampland Program, I will explain why it is natural to identify this QG cutoff with the Species Scale, motivating it by direct computation in the presence of the relevant towers. Then, I will present evidence for this proposal by directly studying how it is realized in different string theory setups, where the kinetic terms of scalars, p-forms and even scalar potentials can be shown…

  • November 07, 2022 11:00 AM
Speaker: Fernando Marchesano
Title: EFT strings and emergence
Venue: CMSA Room G10

Swampland Seminar Speaker: Fernando Marchesano (IFT Madrid) Title: EFT strings and emergence Abstract: We revisit the Emergence Proposal in 4d N=2 vector multiplet sectors that arise from  type II string Calabi-Yau compactifications, with emphasis on the role of axionic fundamental strings, or EFT strings. We focus on large-volume type IIA compactifications, where EFT strings arise from NS5-branes wrapping internal four-cycles, and consider a set of infinite-distance moduli-space limits that can be classified in terms of a scaling weight w=1,2,3. It has been shown before how one-loop threshold effects of an infinite tower of BPS particles made up of D2/D0-branes generate the asymptotic behaviour of  the gauge kinetic functions along limits with $w=3$. We extend this result to w=2 limits, by taking…

  • October 24, 2022 11:00 AM
Speaker: Paul-Konstantin Oehlmann
Title: Anomalies of Discrete Gauge Symmetries and their Cancellation in 6D F-theory
Venue: CMSA Room G10

Swampland Seminar Speaker: Paul-Konstantin Oehlmann(Northeastern) Title: Anomalies of Discrete Gauge Symmetries and their Cancellation in 6D F-theory Abstract: We consider 6D SUGRAs with a discrete gauge group G, engineered via F-theory compactifications on genus-one fibered threefolds. We argue that group G suffers from Dai-Freed anomalies that can be canceled via a discrete Green-Schwarz mechanism. We comment on the ambiguity to assign this GS term in the 7D Anomaly theory which leads to choices that are not all compatible with F-theory. In F-theory we then deduce this Anomaly coefficient explicitly by computing the elliptic genera of the non-critical strings that couple to the 6D two-form fields: Their 2D worldsheet theories inherits a G Flavor symmetries whose t’Hooft anomaly cancels the 6D Dai-Freed anomaly in the…

  • October 11, 2022 11:00 AM
Speaker: Aasmund Folkestad
Title: The Penrose Inequality as a Constraint on Low Energy Quantum Gravity
Venue: CMSA Room G10

Swampland Seminar Speaker: Aasmund Folkestad (MIT) Title: The Penrose Inequality as a Constraint on Low Energy Quantum Gravity Abstract: In this talk, I argue that the Penrose inequality (PI) can be used to constrain low energy theories compatible AdS/CFT, and possibly also quantum gravity in flat space. Focusing on AdS/CFT, it is shown that the PI can be violated for minimally coupled scalar fields, and I produce exclusion plots on couplings that respect the PI. I also present numerical evidence that top-down scalar theories and supersymmetric theories respect the PI. Finally, similar to the Breitenlohner-Freedman bound, I give a necessary condition for the stability AdS that constrains coupling constants (beyond the scalar mass).

  • September 19, 2022 11:00 AM
Speaker: Samir Mathur
Title: The story of the information paradox
Venue: CMSA Room G10

Swampland Seminar Speaker: Samir Mathur (Ohio State) Title: The story of the information paradox Abstract:  In 1975 Hawking argued that black hole evaporation would lead to a loss of unitarity in quantum theory.  The small corrections theorem made Hawking’s argument into a precise statement: if semiclassical physics hold to leading order in any gently curved region of spacetime, then there can be no resolution to the paradox. In string theory, whenever people have been able to construct microstates explicutly, the states turned out to be horizon sized objects (fuzzballs) with no horizon; such a structure of microstates resolves the information paradox since their is no pair creation at a vacuum horizon. There have been a set of parallel attempts to…

  • May 09, 2022 01:00 PM
Speaker: Georges Obie
Title: Inflation and light Dark Matter constraints from the Swampland
Venue: Virtual

Abstract: I will explore the interplay between Swampland conjectures and models of inflation and light Dark Matter. To that end, I will briefly review the weak gravity conjecture (WGC) and the related Festina Lente (FL) bound. These have implications for light darkly and milli-charged particles and can disfavor a large portion of parameter space. The FL bound also implies strong restrictions on the field content of our universe during inflation and presents an opportunity for inflationary model building. At the same time, it rules out some popular models like chromo-natural inflation and gauge-flation. Finally, I will review  another Swampland conjecture related to Stückelberg photon masses and discuss its implications for astro-particle physics.

  • April 18, 2022 01:00 PM
Speaker: José Calderón
Title: 4/18/2022 Swampland Seminar
Venue: Virtual

Open mic Swampland Discussion Topic: Cobordism

  • April 11, 2022 10:00 AM
Speaker: Timm Wrase and Eduardo Gonzalo (Lehigh)
Title: Type IIB flux compactifications with $h^{1,1}=0$
Venue: virtual

Abstract: We revisit type IIB flux compactification that are mirror dual to type IIA on rigid Calabi-Yau manifolds. We find a variety of interesting new solutions, like fully stabilized Minkowski vacua and infinite families of AdS$_4$ solutions with arbitrarily large numbers of spacetime filling D3 branes. We discuss how these solutions fit into the web of swampland conjectures.

  • April 04, 2022 10:00 AM
Speaker: Simon Caron-Huot (McGill University) and Julio Parra (Caltech)
Title: Causality constraints on corrections to Einstein gravity
Venue: virtual

Swampland Seminar Speakers: Simon Caron-Huot (McGill University) and Julio Parra (Caltech) Title: Causality constraints on corrections to Einstein gravity Abstract: We study constraints from causality and unitarity on 2→2 graviton scattering in four-dimensional weakly-coupled effective field theories. Together, causality and unitarity imply dispersion relations that connect low-energy observables to high-energy data. Using such dispersion relations, we derive two-sided bounds on gravitational Wilson coefficients in terms of the mass M of new higher-spin states. Our bounds imply that gravitational interactions must shut off uniformly in the limit G→0, and prove the scaling with M expected from dimensional analysis (up to an infrared logarithm). We speculate that causality, together with the non-observation of gravitationally-coupled higher-spin states at colliders, severely restricts modifications to Einstein gravity that could be probed by experiments in the near future.

  • March 28, 2022 01:00 PM
Speaker: Fernando Quevedo
Title: On renormalisation group induced moduli stabilisation and brane-antibrane inflation
Venue: Virtual

Abstract: A proposal to use the renormalisation group to address moduli stabilisation in IIB string perturbation theory will be described. We revisit brane-antibrane inflation combining this proposal with non-linearly realised supersymmetry.

  • March 21, 2022 01:00 PM
Speaker: Patrick Draper (Univ. of Illinois) and Alvaro Herraez (IPhT Saclay)
Title: 3/21/2022 – Swampland Seminar
Venue: Virtual

Open Mic Discussion Topic: Entropy bounds (species bound, Bekenstein bound, CKN bound, and the like)

  • March 07, 2022 10:00 AM
Speaker: Fernando Marchesano (UAM-CSIC, Madrid) and Max Wiesner (Harvard CMSA)
Title: 4d strings at strong coupling
Venue: virtual

Speakers: Fernando Marchesano (UAM-CSIC, Madrid)  and Max Wiesner (Harvard CMSA) Title: 4d strings at strong coupling As usual, the format will be 45 min talk + 30 min discussion, to encourage participation from the audience. Looking forward to seeing you there!

  • February 28, 2022 01:00 PM
Speaker: Tom Rudelius
Title: Generalized Global Symmetries and the Weak Gravity Conjecture
Venue: Virtual