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1705 - 1716 of 3073 Results

Impossible symmetry enriched topological phases in 2D and their realization on 3D surface

Xie Chen California Institute of Technology
May 07, 2013

PIRSA:13050033
High Energy Physics
Field theory, Wave function, and Defects of Symmetry Protected Topological Phases

Cenke Xu University of California, Santa Barbara
May 07, 2013

PIRSA:13050031
High Energy Physics
Asymmetry protected emergent E8 symmetry

Brian Swingle Brandeis University
May 06, 2013

PIRSA:13050027
High Energy Physics
Protected edge modes without symmetry

Michael Levin University of Chicago
May 06, 2013

PIRSA:13050026
High Energy Physics
AMS02 results support the secondary origin of cosmic ray positrons

Kfir Blum
May 03, 2013

PIRSA:13050015
High Energy Physics
An Infalling Observer in AdS/CFT and the Information Paradox

Suvrat Raju
May 03, 2013

PIRSA:13050016
High Energy Physics
Gromov-Witten Invariants from 2D Gauge Theories

Joshua Lapan Harvard University
April 30, 2013

PIRSA:13040141
High Energy Physics
From topological insulator to weak scale flavor physics

Sichun Sun University of Washington
April 30, 2013

PIRSA:13040126
High Energy Physics
12/13 PSI - Explorations in String Theory Lecture 15

Pedro Vieira Perimeter Institute for Theoretical Physics
April 26, 2013

PIRSA:13040102
High Energy Physics
Higgs Boson in Condensed Matter: From Polaron to Topological Insulator
April 25, 2013

PIRSA:13040132
High Energy Physics

Condensed Matter
12/13 PSI - Explorations in String Theory Lecture 14

Pedro Vieira Perimeter Institute for Theoretical Physics
April 25, 2013

PIRSA:13040101
High Energy Physics
12/13 PSI - Explorations in String Theory Lecture 13

Pedro Vieira Perimeter Institute for Theoretical Physics
April 24, 2013

PIRSA:13040100
High Energy Physics

Impossible symmetry enriched topological phases in 2D and their realization on 3D surface

Xie Chen California Institute of Technology
May 07, 2013

PIRSA:13050033
High Energy Physics
In quantum systems with symmetry, the same topological phase can be enriched by symmetry in different ways, resulting in different symmetry transformations of the superselection sectors in the phase. However, not all symmetry transformations are allowed on the superselection sectors in topological phases in purely 2D systems. In this talk, I will discuss some examples of such symmetry enrichment of topological phases, which seem to be consistent with the fusion and braiding rules of the superselection sectors in the theory but are nonetheless impossible to realize in 2D. Interestingly, we show further that they can be realized on the surface of a 3D gapped system with a topologically trivial bulk.
Field theory, Wave function, and Defects of Symmetry Protected Topological Phases

Cenke Xu University of California, Santa Barbara
May 07, 2013

PIRSA:13050031
High Energy Physics
Asymmetry protected emergent E8 symmetry

Brian Swingle Brandeis University
May 06, 2013

PIRSA:13050027
High Energy Physics
The E8 state of bosons is a 2+1d gapped phase of matter which has no topological entanglement entropy but has protected chiral edge states in the absence of any symmetry. This peculiar state is interesting in part because it sits at the boundary between short- and long-range entangled phases of matter. When the system is translation invariant and for special choices of parameters, the edge states form the chiral half of a 1+1d conformal field theory - an E8 level 1 Wess-Zumino-Witten model. However, in general the velocities of different edge channels are different and the system does not have conformal symmetry. We show that by considering the most general microscopic Hamiltonian, in particular by relaxing the constraint of translation invariance and adding disorder, conformal symmetry remerges in the low energy limit. The disordered fixed point has all velocities equal and is the E8 level 1 WZW model. Hence a highly entangled and highly symmetric system emerges, but only when the microscopic Hamiltonian is completely asymmetric.
Protected edge modes without symmetry

Michael Levin University of Chicago
May 06, 2013

PIRSA:13050026
High Energy Physics
Some 2D quantum many-body systems with a bulk energy gap support gapless edge modes which are extremely robust. These modes cannot be gapped out or localized by general classes of interactions or disorder at the edge: they are "protected" by the structure of the bulk phase. Examples of this phenomena include quantum Hall states and 2D topological insulators, among others. Recently, much progress has been made in understanding protected edge modes in non-interacting fermion systems. However, less is known about the interacting case. A basic problem is to predict, for general interacting systems, when such edge modes are present or absent, and to identify the different physical mechanisms that underlie their stability. In this talk, I will discuss this problem in the simplest case: interacting fermion systems without any symmetry.
AMS02 results support the secondary origin of cosmic ray positrons

Kfir Blum
May 03, 2013

PIRSA:13050015
High Energy Physics
We show that the recent AMS02 positron fraction measurement is perfectly consistent with a secondary origin for positrons, and does not require additional primary sources such as pulsars or dark matter. Within the secondary model the AMS02 data imply a cosmic ray propagation time in the
Galaxy of about one Myr and an average traversed interstellar matter density of about 1/cc at a rigidity of 300 GV. These results may hint that high energy cosmic rays are confined to a thin halo of scale height similar to the gaseous disk.
An Infalling Observer in AdS/CFT and the Information Paradox

Suvrat Raju
May 03, 2013

PIRSA:13050016
High Energy Physics
We reconstruct the experience of an infalling observer using the AdS/CFT correspondence. We write operators both outside and inside the black hole in terms of CFT operators. Our construction provides a natural realization of black hole complementarity, and a way of preserving information without the need for firewalls.
Gromov-Witten Invariants from 2D Gauge Theories

Joshua Lapan Harvard University
April 30, 2013

PIRSA:13040141
High Energy Physics
It has been known for twenty years that a class of two-dimensional gauge theories are intimately connected to toric geometry, as well as to hypersurfaces or complete intersections in a toric varieties, and to generalizations thereof. Under renormalization group flow, the two-dimensional gauge theory flows to a conformal field theory that describes string propagation on the associated geometry. This provides a connection between certain quantities in the gauge theory and topological invariants of the associated geometry. In this talk, I will explain how recent results show that, for Calabi-Yau geometries, the partition function for each gauge theory computes the Kahler potential on the Kahler moduli of the associated geometry. The result is expressed in terms of a Barnes' integral and is readily evaluated in a series expansion around special points in the moduli space (e.g., large volume), providing a fairly efficient way to compute Gromov-Witten invariants of the associated geometry.
From topological insulator to weak scale flavor physics

Sichun Sun University of Washington
April 30, 2013

PIRSA:13040126
High Energy Physics
In this talk, I will start with briefly introducing some universal physics behind quantum hall and topological insulator , which inspired a BSM flavor model. It intimately relates deconstructed little Higgs to flavor structure: fermion masses, CKM etc. This new cousin of little Higgs, we call it little flavor, shares a 10-20 Tev cut-off scale with little Higgs, so as to explain flavor structure at surprisingly low scale without rising FCNC problem.
12/13 PSI - Explorations in String Theory Lecture 15

Pedro Vieira Perimeter Institute for Theoretical Physics
April 26, 2013

PIRSA:13040102
High Energy Physics
Higgs Boson in Condensed Matter: From Polaron to Topological Insulator
April 25, 2013

PIRSA:13040132
High Energy Physics

Condensed Matter
In this talk I will briefly review the polaron physics, which has helped theorists to conceive the BCS theory of conventional superconductors as well as experimentalists to discover high temperature superconductors in the cuprates. Specifically I will talk about how charge carriers obtain their
masses from coupling to the phonon field in one, two, three or higher dimensions. More recently, there is increasing interest in topological insulators where a gap can be opened which may suggest new version of Higgs mechanism in condensed matter.
12/13 PSI - Explorations in String Theory Lecture 14

Pedro Vieira Perimeter Institute for Theoretical Physics
April 25, 2013

PIRSA:13040101
High Energy Physics
12/13 PSI - Explorations in String Theory Lecture 13

Pedro Vieira Perimeter Institute for Theoretical Physics
April 24, 2013

PIRSA:13040100
High Energy Physics

Title	Date	Collection	Type	Info
Impossible symmetry enriched topological phases in 2D and their realization on 3D surface	2013‑05‑07	Emergence & Entanglement II 2013	Conference	View details
Field theory, Wave function, and Defects of Symmetry Protected Topological Phases	2013‑05‑07	Emergence & Entanglement II 2013	Conference	View details
Asymmetry protected emergent E8 symmetry	2013‑05‑06	Emergence & Entanglement II 2013	Conference	View details
Protected edge modes without symmetry	2013‑05‑06	Emergence & Entanglement II 2013	Conference	View details
AMS02 results support the secondary origin of cosmic ray positrons	2013‑05‑03		Scientific Series	View details
An Infalling Observer in AdS/CFT and the Information Paradox	2013‑05‑03	Quantum Fields and Strings	Scientific Series	View details
Gromov-Witten Invariants from 2D Gauge Theories	2013‑04‑30	Quantum Fields and Strings	Scientific Series	View details
From topological insulator to weak scale flavor physics	2013‑04‑30	Particle Physics	Scientific Series	View details
12/13 PSI - Explorations in String Theory Lecture 15	2013‑04‑26	12/13 PSI - Eplorations in String Theory	Course	View details
Higgs Boson in Condensed Matter: From Polaron to Topological Insulator	2013‑04‑25	4 Corner Southwest Symposium 2013	Conference	View details
12/13 PSI - Explorations in String Theory Lecture 14	2013‑04‑25	12/13 PSI - Eplorations in String Theory	Course	View details
12/13 PSI - Explorations in String Theory Lecture 13	2013‑04‑24	12/13 PSI - Eplorations in String Theory	Course	View details

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Impossible symmetry enriched topological phases in 2D and their realization on 3D surface

Field theory, Wave function, and Defects of Symmetry Protected Topological Phases

Asymmetry protected emergent E8 symmetry

Protected edge modes without symmetry

AMS02 results support the secondary origin of cosmic ray positrons

An Infalling Observer in AdS/CFT and the Information Paradox

Gromov-Witten Invariants from 2D Gauge Theories

From topological insulator to weak scale flavor physics

12/13 PSI - Explorations in String Theory Lecture 15

Higgs Boson in Condensed Matter: From Polaron to Topological Insulator

12/13 PSI - Explorations in String Theory Lecture 14

12/13 PSI - Explorations in String Theory Lecture 13

Impossible symmetry enriched topological phases in 2D and their realization on 3D surface

Field theory, Wave function, and Defects of Symmetry Protected Topological Phases

Asymmetry protected emergent E8 symmetry

Protected edge modes without symmetry

AMS02 results support the secondary origin of cosmic ray positrons

An Infalling Observer in AdS/CFT and the Information Paradox

Gromov-Witten Invariants from 2D Gauge Theories

From topological insulator to weak scale flavor physics

12/13 PSI - Explorations in String Theory Lecture 15

Higgs Boson in Condensed Matter: From Polaron to Topological Insulator

12/13 PSI - Explorations in String Theory Lecture 14

12/13 PSI - Explorations in String Theory Lecture 13