Talks

10813 - 10824 of 16962 Results

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

January 21, 2013

PIRSA:13010105

Quantum Information
12/13 PSI - Found Quantum Mechanics Lecture 11

Robert Spekkens Perimeter Institute for Theoretical Physics

January 21, 2013

PIRSA:13010080

Quantum Fields and Strings
12/13 PSI - String Theory Review Lecture 11

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

January 21, 2013

PIRSA:13010061

Quantum Fields and Strings
12/13 PSI - Standard Model Review Lecture 11

Mark Wise California Institute of Technology (Caltech)

January 21, 2013

PIRSA:13010038

Particle Physics
Indirect Searches for Dark Matter with the Fermi Large Area Telescope

Andrea Marie Albert Ohio State University

January 18, 2013

PIRSA:13010102

Particle Physics
12/13 PSI - Found Quantum Mechanics Lecture 10

Robert Spekkens Perimeter Institute for Theoretical Physics

January 18, 2013

PIRSA:13010077

Quantum Fields and Strings

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

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
12/13 PSI - Found Quantum Mechanics Lecture 11

Robert Spekkens Perimeter Institute for Theoretical Physics

January 21, 2013

PIRSA:13010080

Quantum Fields and Strings
12/13 PSI - String Theory Review Lecture 11

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

January 21, 2013

PIRSA:13010061

Quantum Fields and Strings
12/13 PSI - Standard Model Review Lecture 11

Mark Wise California Institute of Technology (Caltech)

January 21, 2013

PIRSA:13010038

Particle Physics
Indirect Searches for Dark Matter with the Fermi Large Area Telescope

Andrea Marie Albert Ohio State University

January 18, 2013

PIRSA:13010102

Particle Physics

There is overwhelming evidence that non-baryonic dark matter constitutes ~23% of the energy density of the universe. Weakly Interacting Massive Particles (WIMPs) are promising dark matter candidates that may produce gamma rays via annihilation or decay detectable by the Fermi Large Area Telescope (Fermi LAT). A detection of WIMPs would also indicate the existence of physics beyond the Standard Model. I will present recent results from indirect WIMP searches by the Fermi LAT Collaboration. I will focus on our recent search for gamma-ray spectral lines from WIMP annihilations with 4 years of data. There has been recent excitement with the report of a line-like feature localized in the galactic center around 130 GeV. I will be discussing what our search finds and the systematic checks we've performed on potential signals.
12/13 PSI - Found Quantum Mechanics Lecture 10

Robert Spekkens Perimeter Institute for Theoretical Physics

January 18, 2013

PIRSA:13010077

Quantum Fields and Strings

Title	Date	Collection	Type	Info
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
12/13 PSI - Found Quantum Mechanics Lecture 11	2013‑01‑21	12/13 PSI - Found Quantum Mechanics	Course	View details
12/13 PSI - String Theory Review Lecture 11	2013‑01‑21	12/13 PSI - String Theory Review	Course	View details
12/13 PSI - Standard Model Review Lecture 11	2013‑01‑21	12/13 PSI - Standard Model Review	Course	View details
Indirect Searches for Dark Matter with the Fermi Large Area Telescope	2013‑01‑18	Particle Physics	Scientific Series	View details
12/13 PSI - Found Quantum Mechanics Lecture 10	2013‑01‑18	12/13 PSI - Found Quantum Mechanics	Course	View details

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