Talks

10297 - 10308 of 16451 Results

What is motion? What is time?

Flavio Mercati
University of Naples Federico II

January 23, 2013

PIRSA:13010003

Quantum Gravity
12/13 PSI - Found Quantum Mechanics Lecture 13

Robert Spekkens
Perimeter Institute for Theoretical Physics

January 23, 2013

PIRSA:13010082

Quantum Fields and Strings
12/13 PSI - String Theory Review Lecture 13

Barton Zwiebach
Massachusetts Institute of Technology (MIT) - Department of Physics

January 23, 2013

PIRSA:13010063

Quantum Fields and Strings
12/13 PSI - Standard Model Review Lecture 13

Mark Wise
California Institute of Technology (Caltech)

January 23, 2013

PIRSA:13010040

Particle Physics
Advanced General Relativity - Lecture 1

Rafael Sorkin
Perimeter Institute for Theoretical Physics

January 22, 2013

PIRSA:13010006
Superfluid to normal phase transition in strongly interacting bosons in two and three dimensions.

Juan Carrasquilla
ETH Zurich

January 22, 2013

PIRSA:13010107

Condensed Matter
A monodromy defect in the 3d Ising model.

Roberto Pellegrini
National Institute for Nuclear Physics

January 22, 2013

PIRSA:13010106

Quantum Fields and Strings
12/13 PSI - Found Quantum Mechanics Lecture 12

Robert Spekkens
Perimeter Institute for Theoretical Physics

January 22, 2013

PIRSA:13010081

Quantum Fields and Strings
Holographic description of cosmological singularity

Misha Smolkin
Hebrew University of Jerusalem

January 22, 2013

PIRSA:13010111

Cosmology
12/13 PSI - String Theory Review Lecture 12

Barton Zwiebach
Massachusetts Institute of Technology (MIT) - Department of Physics

January 22, 2013

PIRSA:13010062

Quantum Fields and Strings
12/13 PSI - Standard Model Review Lecture 12

Mark Wise
California Institute of Technology (Caltech)

January 22, 2013

PIRSA:13010039

Particle Physics
Pinning of Fermionic Occupation Numbers

Christian Schilling
ETH Zurich - Institut für Theoretische Physik

January 21, 2013

PIRSA:13010105

Quantum Information

What is motion? What is time?

Flavio Mercati
University of Naples Federico II

January 23, 2013

PIRSA:13010003

Quantum Gravity

I give an account of the Machian approach to dynamics, from Mach's critique of Newton to the work of Barbour, Bertotti, York and O'Murchadha, which culminated in the theory of Shape Dynamics, a new and original way of thinking about General Relativity. I conclude commenting on the present research lines in Shape Dynamics, and the opportunity it offers to solve the problem of time in quantum gravity.

Support for this colloquium is provided by The Templeton Frontiers Program.
12/13 PSI - Found Quantum Mechanics Lecture 13

Robert Spekkens
Perimeter Institute for Theoretical Physics

January 23, 2013

PIRSA:13010082

Quantum Fields and Strings
12/13 PSI - String Theory Review Lecture 13

Barton Zwiebach
Massachusetts Institute of Technology (MIT) - Department of Physics

January 23, 2013

PIRSA:13010063

Quantum Fields and Strings
12/13 PSI - Standard Model Review Lecture 13

Mark Wise
California Institute of Technology (Caltech)

January 23, 2013

PIRSA:13010040

Particle Physics
Advanced General Relativity - Lecture 1

Rafael Sorkin
Perimeter Institute for Theoretical Physics

January 22, 2013

PIRSA:13010006
Superfluid to normal phase transition in strongly interacting bosons in two and three dimensions.

Juan Carrasquilla
ETH Zurich

January 22, 2013

PIRSA:13010107

Condensed Matter

Using quantum Monte Carlo simulations, we investigate the finite-temperature phase diagram of hard-core bosons (XY model) in two- and three-dimensional square lattices. To determine the phase boundaries, we perform a finite-size scaling analysis of the condensate fraction and/or the superfluid stiffness. We then discuss how this diagrams can be measured in experiments with trapped ultracold gases, where the systems are inhomogeneous. For that, we introduce a method based on the measurement of the zero-momentum occupation, which is adequate for experiments dealing with both homogeneous and trapped systems. Finally, we provide an analytical argument that demonstrates that the Bose-Hubbard model does not exhibit ﬁnite-temperature BEC in two dimensions, provided that density remains finite across the entire system in the thermodynamic limit.
A monodromy defect in the 3d Ising model.

Roberto Pellegrini
National Institute for Nuclear Physics

January 22, 2013

PIRSA:13010106

Quantum Fields and Strings

A conformal defect is a d-dimensional geometrical object that breaks the SO(D+1,1) symmetry, of a D-dimensional conformal field theory, down to those transformations that leave the defect invariant i.e. SO(D-d) X SO(d+1,1).
We studied the 3D critical Ising model in presence of a special kind of these defects, a monodromy line defect.
In particular we computed, using Montecarlo simulations, the anomalous dimensions of the lowest dimensional operators living at the defect, as well as correlation functions of operators in the bulk with operators at the defect.
We found a good agreement between our results and the expectations of conformal field theory.
12/13 PSI - Found Quantum Mechanics Lecture 12

Robert Spekkens
Perimeter Institute for Theoretical Physics

January 22, 2013

PIRSA:13010081

Quantum Fields and Strings
Holographic description of cosmological singularity

Misha Smolkin
Hebrew University of Jerusalem

January 22, 2013

PIRSA:13010111

Cosmology

In my talk I will discuss our recent paper hep-th/1211.1322 where we construct a 3D conformal field theory dual to asymptotically AdS cosmology in four dimensions. Due to the scale invariance this dual theory allows an infinite family of instantons each of which breaks the conformal group O(3,2) down to O(3,1). These instantons are dual to bulk instantons responsible for nucleating an O(3,1) invariant cosmological bubble. Presumably they indicate an infinite instability rate, however we are able to sum over all of them completely. The resulting theory is manifestly stable, unitary and finite.
12/13 PSI - String Theory Review Lecture 12

Barton Zwiebach
Massachusetts Institute of Technology (MIT) - Department of Physics

January 22, 2013

PIRSA:13010062

Quantum Fields and Strings
12/13 PSI - Standard Model Review Lecture 12

Mark Wise
California Institute of Technology (Caltech)

January 22, 2013

PIRSA:13010039

Particle Physics
Pinning of Fermionic Occupation Numbers

Christian Schilling
ETH Zurich - Institut für Theoretische Physik

January 21, 2013

PIRSA:13010105

Quantum Information

The problem of determining and describing the family of 1-particle reduced density operators (1-RDO) arising from N-fermion pure states (viapartial trace) is known as the fermionic quantum marginal problem. We present its solution, a multitude of constraints on the eigenvalues of the 1-RDO, generalizing the Pauli exclusion principle. To explore the relevance of these constraints we study an analytically solvable model of N fermions in a harmonic potential and determine the spectral `trajectory' corresponding to the ground state as function of the fermion-fermion interaction strength.Intriguingly, we find that the occupation numbers are almost, but not exactly, pinned to the boundary of the allowed region (quasi-pinned). Our findings suggest a generalization of the Hartree-Fock approximation.

see also: http://arxiv.org/abs/1210.5531

Title	Date	Collection	Type	Info
What is motion? What is time?	2013‑01‑23	Colloquium	Scientific Series	View details
12/13 PSI - Found Quantum Mechanics Lecture 13	2013‑01‑23	12/13 PSI - Found Quantum Mechanics	Course	View details
12/13 PSI - String Theory Review Lecture 13	2013‑01‑23	12/13 PSI - String Theory Review	Course	View details
12/13 PSI - Standard Model Review Lecture 13	2013‑01‑23	12/13 PSI - Standard Model Review	Course	View details
Advanced General Relativity - Lecture 1	2013‑01‑22	Elements of General Relativity	Course	View details
Superfluid to normal phase transition in strongly interacting bosons in two and three dimensions.	2013‑01‑22	Quantum Matter	Scientific Series	View details
A monodromy defect in the 3d Ising model.	2013‑01‑22	Quantum Fields and Strings	Scientific Series	View details
12/13 PSI - Found Quantum Mechanics Lecture 12	2013‑01‑22	12/13 PSI - Found Quantum Mechanics	Course	View details
Holographic description of cosmological singularity	2013‑01‑22	Cosmology and Gravitation	Scientific Series	View details
12/13 PSI - String Theory Review Lecture 12	2013‑01‑22	12/13 PSI - String Theory Review	Course	View details
12/13 PSI - Standard Model Review Lecture 12	2013‑01‑22	12/13 PSI - Standard Model Review	Course	View details
Pinning of Fermionic Occupation Numbers	2013‑01‑21	Perimeter Institute Quantum Discussions	Scientific Series	View details

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