# Events Archive

## High Energy Theory Seminar

### HET Seminar | Sergei Dubovsky, NYU | "On confining strings in diverse dimensions" | Jadwin A06

Mon, Nov 5, 2018, 3:00 pm

* Please note the special time and room. *

Speaker(s):

### HET Seminar | Tudor Dimofte, UC Davis | "Higher algebraic structures in SUSY QFT" | PCTS Seminar Room

Mon, Oct 22, 2018, 2:30 pm

In a TQFT of homological type, such as arises from the topological twist of a supersymmetric theory, it is well known that the local operators form an algebra, associative in dimension d >= 1 and commutative in d >= 2. The product comes from collision of operators.

Speaker(s):

### HET Seminar | Avner Karasik, Weizmann Institute | "On the phase diagram of SU(N)XSU(N) gauge theory with bifundamental Fermion" | PCTS Seminar Room

Fri, Oct 12, 2018, 1:45 pm

We study the phase diagram of SU(N)XSU(N) gauge theory with massive bifundamental Fermion at zero temperature. Assuming that the theory is confining and gapped, some constraints that come from anomalies can be put on the phase diagram as a function of the two theta- angles.

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### HET Seminar | Miroslav Rapcak, Perimeter Institute | "The Vertex Operator Algebra Vertex" | PCTS Seminar Room

Tue, Oct 9, 2018, 3:00 pm

Over the past two decades, Vertex Operator Algebras (VOA) have appeared in various contexts in gauge theory. I will discuss a class of VOAs arising as algebras of local operators at junctions of interfaces in four-dimensional N=4 super Yang-Mills theory.

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### HET Seminar | Martin Kruczenski, Purdue University | “The S-matrix bootstrap for the 2d O(N) non-linear sigma model" | PCTS Seminar Room

Mon, Oct 8, 2018, 2:30 pm

In this talk I will discuss how to apply the S-matrix bootstrap maximization program to the 2d bosonic O(N) integrable model which has N species of scalar particles with mass m and no bound states.

Speaker(s):

### HET Seminar | Amos Yarom, Technion & Princeton University | "New constraints on transport from Schwinger Keldysh theory" | PCTS Seminar Room

Fri, Sep 28, 2018, 1:45 pm

After a review of a novel low energy effective action for the Schwinger-Keldysh generating function, I will describe how it captures information on the entropy current, Onsager relations, and new constraints on transport.

Speaker(s):

### HET Seminar | Vladimir Narovlansky, Weizmann Institute | "Exact correlation functions in double-scaled SYK" | PCTS Seminar Room

Tue, Sep 25, 2018, 2:00 pm

We show that exact results (at all energy scales) can be obtained in double-scaled SYK, which is the usual SYK model with the number of fermions in the interaction scaling as \sqrt{N}. These include the calculation of the full four-point function. The analysis does not involve summations of Feynman diagrams, but rather uses combinatorial tools...

Speaker(s):

### HET Seminar | Masataka Watanabe, University of Tokyo & Kavli IPMU | "The Large Charge Expansion and the Universal Correlation Functions in Rank-1 SCFT" | PCTS Seminar Room

Mon, Sep 24, 2018, 2:30 pm

The two-point functions <O^n(x) Obar^n(y)> for generator O of Coulomb branch chiral rings in D=4 N=2 SCFT will be determined universally to all orders in 1/n by the theory's a-anomaly.

Speaker(s):

### HET Seminar | Bernard Julia, LPT-ENS | "Exceptional families of symmetries" | PCTS Seminar Room

Fri, Sep 14, 2018, 1:45 pm

It is important to understand the origin of exceptional symmetries like E7 duality in 4d M-Sugra. Depending on the context and the defining property at work (anomaly or divergence cancellation, attractor mechanism, classification of supergauge theories in 4, 5 or 6d, 2d integrable systems...) the En groups appear in various families.

Speaker(s):

### HET Seminar | David Kutasov, University of Chicago | "Solvable irrelevant deformations of CFT_2 and AdS_3" | PCTS Seminar Room

Mon, Sep 10, 2018, 2:30 pm

I will describe recent progress on the study of solvable irrelevant deformations of two dimensional conformal field theories, focusing on the torus partition sum of these theories. I will also discuss some related solvable irrelevant deformations of string theory on AdS_3.

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### HET Seminar | Mikhail Vasiliev, Lebedev Physical Institute, Moscow | "From Coxeter Higher-Spin Theories to Strings and Tensor Models" | Jadwin A06

Mon, Apr 23, 2018, 2:30 pm

A new class of higher-spin gauge theories associated with various Coxeter groups is proposed. The emphasize  is on the $B_p$--models. The multi-particle $B_2$--higher-spin theory is conjectured to be associated with String Theory. $B_p$--higher-spin models with $p>2$ are anticipated to be dual to the rank-$p$ boundary tensor sigma-models.

Speaker(s):

### HET Seminar | Sarah Harrison, McGill | "Borcherds Kac-Moody Algebras and BPS States in String Theory" | PCTS Seminar Room

Fri, Apr 13, 2018, 1:45 pm

Abstract: Borcherds Kac-Moody (BKM) algebras are a generalization of familiar Kac-Moody algebras with imaginary simple roots. On the one hand, they were invented by Borcherds in his proof of the monstrous moonshine conjectures and have many interesting connections to new moonshines, number theory and the theory of automorphic...

Speaker(s):

### HET Seminar | Huajia Wang, UIllinois Urbana-Champaign | "Probing beyond ETH at large $c$" | Jadwin A06

Mon, Apr 9, 2018, 2:30 pm

Eigenstate thermalization hypothesis (ETH) is a phenomena often observed in systems characterized by quantum chaos. In this talk, we study ETH in 2d CFTs with large central charges. In particular, we focus on observables consisting of bilocal "probe" operators $\mathcal{O}_L(x)\mathcal{O}_L(0)$.

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### HET Seminar at IAS | Cumrun Vafa, Harvard University | “6d Theories on Circle and Curves”

Mon, Apr 2, 2018, 2:30 pm

In this talk I review new results obtained for SCFT's in 4 and 5 dimensions by compactifying 6 dimensional (1,0) SCFT's on a circle or on Riemann surfaces.

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### HET Seminar | Bruno Le Floch, Princeton | "Orbifolds of 4d N=2 supersymmetric gauge theories" | Jadwin A06

Fri, Mar 30, 2018, 1:45 pm

After recalling how some 4d N=2 gauge theories arise from reductions of 6d N=(2,0) superconformal theories on a Riemann surface, I will discuss two discrete quotients with codimension 2 orbifold singularities.  In the first case the orbifold acts by rotations around one plane of the 4d N=2 theory; this is related to a Gukov-Witten surface...

Speaker(s):

### HET Seminar | Shiroman Prakash, Dayalbagh Educational Institute, Agra | "A Review of Bifundamental Chern-Simons Theories and the M/N Expansion" | PCTS Seminar Room

Wed, Mar 28, 2018, 1:30 pm

In this talk we will review some results and conjectures about non-supersymmetric bifundamental $U(N)\timesU(M)$ Chern-Simons coupled to matter. It is an apparently unique feature of three-dimensions that one can easily define a variety of non-supersymmetric lines of conformal fixed points via the Chern-Simons kinetic term for a gauge field.

Speaker(s):

### HET Seminar | Ibrahima Bah, Johns Hopkins U | "Holographic duals of 6D SCFTs on Riemann Surfaces" | PCTS Seminar Room

Mon, Mar 26, 2018, 2:30 pm

Four-dimensional superconformal field theories can be studied and partially classified by compactifying six-dimensional ones on punctured Riemann surfaces.  In this talk we discuss the holographic dual of this set-up and explore how various gravitational sources encode the data associated to the punctures.

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### HET Seminar at IAS | Guifre Vidal, Perimeter Institute | “Tensor Networks as Geometry”

Mon, Mar 19, 2018, 2:30 pm

The multiscale entanglement renormalization ansatz (MERA) is a tensor network that can efficiently approximate ground states of critical spin chains --that is, lattice versions of 1+1 CFTs. Its network structure extends in an additional dimension corresponding to renormalization group scale.

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### HET Seminar | Thomas Dumitrescu, Harvard | “Fun with 2-Group Global Symmetries” | PCTS Seminar Room

Mon, Mar 12, 2018, 2:30 pm

Quantum field theories can have ordinary global symmetries, as well as generalized higher-form symmetries. 2-group symmetries arise when  a generalized 1-form symmetry mixes with ordinary global symmetries. I will discuss theories with continuous 2-group symmetries in four and six spacetime dimensions.

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