High Energy Physics

Displaying 1729 - 1740 of 3169

Exact results in supersymmetric gauge theories in various dimensions

Sara Pasquetti University of Milan
March 19, 2014

PIRSA:14030084
High Energy Physics
Before the Bang

Raman Sundrum University of Maryland, College Park
March 18, 2014

PIRSA:14030113
High Energy Physics
Black Holes- the Harmonic Oscillators of the 21st Century

Andrew Strominger Harvard University
March 12, 2014

PIRSA:14030104
High Energy Physics
Line Defects and Tropicalization

Clay Cordova University of Chicago
March 11, 2014

PIRSA:14030106
High Energy Physics
How Much Information Can SUSY QM Conserve About SUSY QFT?

S. James Gates Jr. University of Maryland, College Park
March 04, 2014

PIRSA:14030101
High Energy Physics
Large Tensor-to-Scalar Ratio in Small-Field Inflation

Takeshi Kobayashi SISSA International School for Advanced Studies
February 25, 2014

PIRSA:14020152
High Energy Physics

Astrophysics
Quantum Liquids and Turbulent Black Holes

Allan Adams Massachusetts Institute of Technology (MIT) - Department of Physics
February 24, 2014

PIRSA:14020141
High Energy Physics
Sequestering the Standard Model Vacuum Energy

Nemanja Kaloper University of California, Davis
February 21, 2014

PIRSA:14020109
High Energy Physics
Causality, holography, and entanglement entropy
February 20, 2014

PIRSA:14020146
General Relativity & Quantum Cosmology

High Energy Physics

Condensed Matter

General Relativity & Quantum Cosmology
Cluster Polylogarithms for Scattering Amplitudes
February 18, 2014

PIRSA:14020147
High Energy Physics
Towards a 1/c Expansion in 2d Conformal Field Theory
February 04, 2014

PIRSA:14020084
High Energy Physics
Mayer-Cluster Expansion of Instanton Partition Functions and Thermodynamic Bethe Ansatz

Carlo Meneghelli University of Oxford
January 28, 2014

PIRSA:14010096
High Energy Physics

Exact results in supersymmetric gauge theories in various dimensions

Sara Pasquetti University of Milan
March 19, 2014

PIRSA:14030084
High Energy Physics
One of the central challenges in theoretical physics is to develop non-perturbative methods to describe quantitatively the dynamics of strongly coupled quantum fields. Much progress in this direction has been made for theories with a higher degree of symmetry, such as conformal symmetry or supersymmetry. In recent years the method of localisation has allowed to obtain a great deal of exact results for supersymmetric gauge theories in various dimensions which has led to the discovery of new surprising correspondences such as the celebrated Alday-Gaiotto-Tachikawa correspondence. I will review some recent results which indicate that partition functions of supersymmetric theories formulated on compact manifolds can be expressed in terms of a small set of fundamental building blocks.
Before the Bang

Raman Sundrum University of Maryland, College Park
March 18, 2014

PIRSA:14030113
High Energy Physics
The simplest black hole solution in asymptotic AdS spacetime, the eternal 3-dimensional BTZ black hole, is studied from the viewpoint of AdS/CFT duality. We identify a class of non-local correlators on the CFT side that allow us to generalize the notion of quantum gravity "S-matrix" to scattering inside the horizon. Since the interior of the horizon is a cosmological spacetime with a big bang/crunch-like singularity, our construction can be interpreted as identifying generally coordinate invariant observables of quantum gravity in a simple cosmology. We show in a certain precise sense, that these holographic observables lie "before the big bang" in a region of spacetime containing closed timelike curves. A central tool in our analysis is the realization of BTZ as a quotient of 3-dimensional AdS.
Black Holes- the Harmonic Oscillators of the 21st Century

Andrew Strominger Harvard University
March 12, 2014

PIRSA:14030104
High Energy Physics
In the twentieth century, many problems across all of physics were solved by perturbative methods which reduced them to harmonic oscillators. Black holes are poised to play a similar role for the problems of twenty-first century physics. They are at once the simplest and most complex objects in the physical universe. They are maximally complex in that the number of possible microstates, or entropy, of a black hole is believed to saturate a universal bound. They are maximally simple in that, according to Einstein's theory, they are featureless holes in space characterized only by their mass, charge and angular momentum. This dual relation between simplicity and complexity, as expressed in black holes, has recently been successfully applied to problems in a disparate variety of physical systems. I will give an introduction to the subject intended for a general audience.
Line Defects and Tropicalization

Clay Cordova University of Chicago
March 11, 2014

PIRSA:14030106
High Energy Physics
I will review BPS line defects in 4d N=2 field theories and describe a technique for calculating their spectra using quiver quantum mechanics.
How Much Information Can SUSY QM Conserve About SUSY QFT?

S. James Gates Jr. University of Maryland, College Park
March 04, 2014

PIRSA:14030101
High Energy Physics
In this presentation, evidence is given that supersymmetrical theories may be exceptional in their ability to conserve information about space-time representations under the impact of dimensional compactification. This is the essence of the concept of ``SUSY Holography.''
Large Tensor-to-Scalar Ratio in Small-Field Inflation

Takeshi Kobayashi SISSA International School for Advanced Studies
February 25, 2014

PIRSA:14020152
High Energy Physics

Astrophysics
The production of gravitational waves from cosmic inflation > is normally bounded by the inflaton field excursion. This relation, > which is often referred to as the Lyth bound, claims that > observationally large gravitational waves are produced only if the > inflaton has a super-Planckian field range. In this talk I will point > out that this general belief is not necessarily true when there are > additional light fields producing density perturbations. Perturbations > seeded by the inflaton can be suppressed under such situations, thus > allow large gravitational waves to be produced even from small-field (i.e. > sub-Planckian) inflation. I will also show that the field bound is > taken over by the light field when the inflaton-induced perturbations > are suppressed, thus present a generalized form of the Lyth bound that > applies to the total field space. The calculations are rather simple, > so I will explain my work on a blackboard.
Quantum Liquids and Turbulent Black Holes

Allan Adams Massachusetts Institute of Technology (MIT) - Department of Physics
February 24, 2014

PIRSA:14020141
High Energy Physics
The physics of black hole horizons is intimately connected to the physics of quantum liquids. In this talk I will review the connection and draw lessons about quantum turbulence from black hole dynamics and vice versa. For example, gravitational dynamics reveal that quantum turbulence can behave very differently from normal fluid turbulence in 2d, with long-wavelength excitations rapidly dissolving into small fluctuations and dissipating as in a 3d normal liquid. Meanwhile, familiar facts about turbulent flows in normal fluids imply that the horizons of certain accreting black holes evolve in time as if they have a non-trivial fractal dimension.
Sequestering the Standard Model Vacuum Energy

Nemanja Kaloper University of California, Davis
February 21, 2014

PIRSA:14020109
High Energy Physics
We propose a very simple reformulation of General Relativity, which completely sequesters from gravity {\it all} of the vacuum energy from a matter sector, including all loop corrections and renders all contributions from phase transitions automatically small. The idea is to make the dimensional parameters in the matter sector functionals of the 4-volume element of the universe. For them to be nonzero, the universe should be finite in spacetime. If this matter is the Standard Model of particle physics, our mechanism prevents any of its vacuum energy, classical or quantum, from sourcing the curvature of the universe. The mechanism is consistent with the large hierarchy between the Planck scale, electroweak scale and curvature scale, and early universe cosmology, including inflation. Consequences of our proposal are that the vacuum curvature of an old and large universe is not zero, but very small, that wDE≃−1 is a transient, and that the universe will collapse in the future.
Causality, holography, and entanglement entropy
February 20, 2014

PIRSA:14020146
General Relativity & Quantum Cosmology

High Energy Physics

Condensed Matter

General Relativity & Quantum Cosmology
After giving a brief overview of holographic entanglement entropy formulas, I will explore a curious feature they imply: when the bulk spacetime includes a black hole, the entanglement entropies often appear to depend on the spacetime geometry inside the horizon. I will ask whether this implies any loss of causality in the field theory. To answer this question, I will present a new general-relativity theorem concerning the causal structure of asymptotically AdS spacetimes, which implies an interesting relationship between bulk and boundary causal domains.
Cluster Polylogarithms for Scattering Amplitudes
February 18, 2014

PIRSA:14020147
High Energy Physics
Motivated by the cluster structure of two-loop scattering amplitudes in N = 4 Yang-Mills theory we define cluster polylogarithm functions. We find that all such functions of weight 4 are made up of a single simple building block associated to the A2 cluster algebra. Adding the requirement of locality on generalized Stasheff polytopes, we find that these A2 building blocks arrange themselves to form a unique function associated to the A3 cluster algebra. ThisA3 function manifests all of the cluster algebraic structure of the two-loop n-particle MHV amplitudes for all n, and we use it to provide an explicit representation for the most complicated part of the n = 7 amplitude as an example.
Towards a 1/c Expansion in 2d Conformal Field Theory
February 04, 2014

PIRSA:14020084
High Energy Physics
I will describe progress in deriving 3d gravity directly from 2d conformal field theory at large central charge 'c'. In a large class of CFTs, using general arguments like modular invariance, crossing symmetry, and the OPE expansion, the spectrum, the entanglement entropy, and certain partition functions can be computed to leading order in a 1/c expansion. The results agree with universal features of 3d gravity required by black hole thermodynamics and the Ryu-Takayanagi formula; furthermore, the relevant 3d geometries appear automatically from CFT calculations in this regime.
Mayer-Cluster Expansion of Instanton Partition Functions and Thermodynamic Bethe Ansatz

Carlo Meneghelli University of Oxford
January 28, 2014

PIRSA:14010096
High Energy Physics
In arXiv:0908.4052, Nekrasov and Shatashvili pointed out that the N=2 instanton partition function in a special limit of the Omega-deformation parameters is characterized by certain thermodynamic Bethe ansatz (TBA) like equations.In this talk I will present an explicit derivation of this fact as well as generalizations to quiver gauge theories. The TBA equations derived entirely within gauge theory have been proposed to encode the spectrum of a large class of quantum integrable systems. I will conclude with some remarks on this correspondence.

Title	Speaker(s)	Date	Talk Type	Info link
Exact results in supersymmetric gauge theories in various dimensions	Sara Pasquetti	2014-03-19	Scientific Series	View details
Before the Bang	Raman Sundrum	2014-03-18	Scientific Series	View details
Black Holes- the Harmonic Oscillators of the 21st Century	Andrew Strominger	2014-03-12	Scientific Series	View details
Line Defects and Tropicalization	Clay Cordova	2014-03-11	Scientific Series	View details
How Much Information Can SUSY QM Conserve About SUSY QFT?	S. James Gates Jr.	2014-03-04	Scientific Series	View details
Large Tensor-to-Scalar Ratio in Small-Field Inflation	Takeshi Kobayashi	2014-02-25	Scientific Series	View details
Quantum Liquids and Turbulent Black Holes	Allan Adams	2014-02-24	Scientific Series	View details
Sequestering the Standard Model Vacuum Energy	Nemanja Kaloper	2014-02-21	Scientific Series	View details
Causality, holography, and entanglement entropy		2014-02-20	Scientific Series	View details
Cluster Polylogarithms for Scattering Amplitudes		2014-02-18	Scientific Series	View details
Towards a 1/c Expansion in 2d Conformal Field Theory		2014-02-04	Scientific Series	View details
Mayer-Cluster Expansion of Instanton Partition Functions and Thermodynamic Bethe Ansatz	Carlo Meneghelli	2014-01-28	Scientific Series	View details

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High Energy Physics

Format results

Exact results in supersymmetric gauge theories in various dimensions

Before the Bang

Black Holes- the Harmonic Oscillators of the 21st Century

Line Defects and Tropicalization

How Much Information Can SUSY QM Conserve About SUSY QFT?

Large Tensor-to-Scalar Ratio in Small-Field Inflation

Quantum Liquids and Turbulent Black Holes

Sequestering the Standard Model Vacuum Energy

Causality, holography, and entanglement entropy

Cluster Polylogarithms for Scattering Amplitudes

Towards a 1/c Expansion in 2d Conformal Field Theory

Mayer-Cluster Expansion of Instanton Partition Functions and Thermodynamic Bethe Ansatz

Exact results in supersymmetric gauge theories in various dimensions

Before the Bang

Black Holes- the Harmonic Oscillators of the 21st Century

Line Defects and Tropicalization

How Much Information Can SUSY QM Conserve About SUSY QFT?

Large Tensor-to-Scalar Ratio in Small-Field Inflation

Quantum Liquids and Turbulent Black Holes

Sequestering the Standard Model Vacuum Energy

Causality, holography, and entanglement entropy

Cluster Polylogarithms for Scattering Amplitudes

Towards a 1/c Expansion in 2d Conformal Field Theory

Mayer-Cluster Expansion of Instanton Partition Functions and Thermodynamic Bethe Ansatz