# Events Archive

## 2016

### Physics Group Meeting - IAS - Discussion group led by Pavel Putrov, Member IAS - “Categorification of Chern-Simons Partition Function”

Wed, Mar 23, 2016, 1:30 pm to 2:30 pm

I would like to discuss the problem of categorification of Chern-Simons partition function on closed 3-manifolds. Physics constructions of Khovanov knot homology, which categorifies Jones polynomial, suggests that there should be a generalization to the case of arbitrary closed 3-manifolds.

### Special Condensed Matter Seminar, Alexey Soluyanov, ETH, "New Topological Excitations"

Wed, Mar 23, 2016, 1:30 pm to 3:00 pm

In recent years it was realized that our knowledge of possible quasiparticle excitations is incomplete even for non-interacting systems. I will talk about several novel topological excitations that appear in metals. One of them realizes a new type of Weyl fermion, hosting the behavior very different from its standard quantum field theory...

### Math Physics Seminar, Robin Reuvers, U of Copenhagen, "The Bogoliubov free energy functional"

Tue, Mar 22, 2016, 4:30 pm to 5:30 pm

Einstein's classic treatment of Bose-Einstein condensation for non-interacting bosons predicts at what temperature the phase transition to BEC occurs, but how this critical temperature changes when the bosons start to interact weakly is an old problem, first posed by Feynman in 1953.

### Pheno & Vino Seminar, Matthew Kleban, NYU, "Inhomogeneous Anisotropic Cosmology"

Tue, Mar 22, 2016, 4:00 pm to 5:30 pm

Very little is known about cosmology away from the homogeneous limit. In this talk I will describe a set of results pertaining to universes with arbitrarily large inhomogeneity and anisotropy.

### High Energy Theory Seminar - Erik Tonni, SISSA - "Some geometrical aspects of entanglement in CFT & Holography"

Mon, Mar 21, 2016, 2:30 pm to 3:30 pm

In the first part we discuss the holographic entanglement entropy in AdS4/CFT3 for finite domains with generic shapes. For smooth shapes the constant term can be evaluated by employing a generalisation of the Willmore functional for two dimensional surfaces. Explicit examples are given for asymptotically AdS4 black holes, domain wall geometries...

### Condensed Matter Seminar, Haim Beidenkopf, Weizmann Institute, "Tantalizing Fermi arcs in a Weyl semi-metal"

Mon, Mar 21, 2016, 1:15 pm to 2:30 pm

A defining property of a topological material is the existence of surface bands that cannot be realized but as the termination of a topological bulk. In a Weyl semi-metal these are given by the surface Fermi-arcs, whose open-contour Fermi-surface curves between pairs of surface projections of bulk Weyl points of opposite chirality.

### Biophysics Seminar - Thierry Mora, ENS

Mon, Mar 21, 2016, 12:00 pm to 1:00 pm

Lunch @ 11:45, seminar 12-1:00

### High Energy Theory Seminar IAS - Sangmin Lee, IAS, Seoul National University - “2d (0,2) Gauge Theories and Calabi-Yau 4-fold Singularities”

Fri, Mar 18, 2016, 1:45 pm to 3:00 pm

We study 2d (0,2) quiver gauge theories on the world-volume of D1-branes probing singular toric Calabi-Yau 4-folds. The gauge theories for arbitrary toric singularities are constructed by means of partial resolution. Each gauge theory is expected to flow to a non-linear sigma model whose target space is the corresponding Calabi-Yau 4-fold or its...

### Physics Group Meeting IAS - Discussion Group led by Leonard Susskind, Stanford University - “ER=EPR and Copenhagen-Everett Duality”

Wed, Mar 16, 2016, 1:30 pm to 2:30 pm

Quantum mechanics is distinguished by three essential features: the Hugeness of Hilbert Space, I.e., the capacity for exponential complexity; the phenomenon of Entanglement; and the duality between Wave Function Collapse and Everett's Relative State Interpretation.

### High Energy Theory Seminar IAS - Leonard Susskind, Stanford University, “Complexity Behind the Horizon”

Mon, Mar 14, 2016, 2:30 pm to 3:30 pm

Quantum mechanics is distinguished by three essential features: the Hugeness of Hilbert Space, I.e., the capacity for exponential complexity; the phenomenon of Entanglement; and the duality between Wave Function Collapse and Everett's Relative State Interpretation.

### Hamilton Colloquium Series - Dam Thanh Son, University of Chicago: "Surprises with Dirac fermions in condensed matter"

Thu, Mar 10, 2016, 4:30 pm to 6:00 pm

Starting with the discovery of graphene, the Dirac equation has appeared in many different contexts in condensed matter physics. In this talk I will describe two recent developments: the effects of chiral anomalies in Weyl and Dirac materials, and the Dirac nature of the composite fermion in the many-body physics of the half-filled Landau level...

### Physics Group Meeting IAS - Discussion Group led by David Kosower, Member IAS;CEA/Saclay - “Integration By Parts for Feynman Integrals”

Wed, Mar 9, 2016, 1:30 pm to 2:30 pm

In this discussion I will present the background to the integration-by-parts (IBP) machinery as used for Feynman integrals, and its applications. I will also discuss recent work linking IBP to some aspects of the algebraic geometry underlying Feynman integrals.
Original IBP paper (pre-arXiv!):
Nucl. Phys. B192 (1981) 159-204 [DOI:

### Math Physics Seminar, Jeffrey Schenker, Michigan State, "Localization in the disordered Holstein model"

Tue, Mar 8, 2016, 4:30 pm to 5:30 pm

The Holstein model (in the one particle sector) describes a lattice particle interacting with independent Harmonic oscillators at each site of the lattice. We consider this model with on site disorder in the particle potential. This is proposed a simple model in which it may be possible to test some ideas regarding multi/many-body localization.

### Pheno & Vino Seminar, Marat Freytsis, "The B -> D(*) tau nu anomalies: facts and/or fictions"

Tue, Mar 8, 2016, 4:00 pm to 5:30 pm

The ratio of the measured B → D(*) l nu decay rates for tau and lighter leptons deviate from the Standard Model (SM) by about 4 standard deviation. I will discuss why the data is in tension with SM predictions, independent of complications in modeling exclusive decays, and complementary measurements that can be made to reduce associated theory...

### Special Condensed Matter Seminar, Chaoxing Liu, Penn State, “Possible realization of bosonic symmetry protected topological phases in bilayer graphe

Tue, Mar 8, 2016, 1:30 pm to 2:30 pm

Ever since the discovery of time reversal invariant topological insulators, intensive research interests are focused on how to identify new topological phases that are protected by symmetry (known as symmetry protected topological states) and how to search for new topological materials to realize these topological phases.

### High Energy Theory - Cumrun Vafa, Harvard University - "F-theory Perspective of 6d/4d SCFT's"

Mon, Mar 7, 2016, 2:30 pm to 3:30 pm

### Biophysics Seminar - Nicolas Desprat, ENS "The morphogenesis of bacterial microcolonies and its role in environmental adaptation"

Mon, Mar 7, 2016, 12:00 pm to 1:00 pm

To colonize surfaces, bacteria must adhere and proliferate. How those terms compete to shape the foundations of biofilm is barely understood. When bacteria grow between a coverslip and a gel pad, they form microcolonies, which develop initially in a plane before terraces establish at their centre.

### Gravity Group Seminar, Jean-Loup Puget (Institut d’Astrophysique Spatiale, Orsay)

Fri, Mar 4, 2016, 3:00 pm to 4:00 pm

TBA

*Note the special time*

### Special Cosmology Seminar, Jean-Loup Puget (IAS, Orsay) "Low multipole polarization measurements from Planck"

Fri, Mar 4, 2016, 3:00 pm to 4:00 pm

Note the special time at 3:00pm

### High Energy Theory Seminar IAS - Mauricio Romo, IAS - “B-brane transport on (non-) abelian gauged linear sigma models”

Fri, Mar 4, 2016, 1:45 pm to 3:00 pm

I will define the hemisphere partition function for B-brane boundary conditions in GLSMs and describe some applications to B-brane transport on spacial classes of (non-) abelian GLSMs.