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Algebraic structures in massive (2,2) theories
Davide Gaiotto Perimeter Institute for Theoretical Physics
PIRSA:13100117 -
Exact Results In Two-Dimensional (2,2) Supersymmetric Gauge Theories With Boundary
Kentaro Hori University of Tokyo
PIRSA:13100116 -
Exact results for boundaries and domain walls in 2d supersymmetric theories
Takuya Okuda University of Tokyo
PIRSA:13100115 -
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Hybrid conformal field theories
PIRSA:13100114 -
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Atomic Physics in the Era of Control: What every physicist should know about the 2012 Physics Nobel Prize
Wes Campbell University of California, Los Angeles
PIRSA:13080042 -
The impact of the Atmosphere on space-bound Vehicles
PIRSA:13080046 -
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Blobbed topological recursion
PIRSA:13100118Hermitian matrix models have been used since the early days of 2d quantum gravity, as generating series of discrete surfaces, and sometimes toy models for string theory. The single trace matrix models (with measure dM exp( - N Tr V(M)) have been solved in a 1/N expansion in the 90s by the moment method of Ambjorn et al. Later, Eynard showed that it can be rewritten more intrinsically in terms of algebraic geometry of the spectral curve, and formulated the so-called topological recursion. In a similar way, we will show that double hermitian matrix models are solved by the same topological recursion, and more generally, that arbitrary hermitian matrix models are solved by a "blobbed topological recursion", whose properties still have to be investigated. -
Algebraic structures in massive (2,2) theories
Davide Gaiotto Perimeter Institute for Theoretical Physics
PIRSA:13100117I will review some ongoing work on the low energy properties of D-branes/boundary conditions in massive two-dimensional field theories with (2,2) supersymmetry. -
Exact Results In Two-Dimensional (2,2) Supersymmetric Gauge Theories With Boundary
Kentaro Hori University of Tokyo
PIRSA:13100116We compute the partition function on the hemisphere of a class of two-dimensional (2,2) supersymmetric field theories including gauged linear sigma models. The result provides a general exact formula for the central charge of the D-brane placed at the boundary. It takes the form of Mellin-Barnes integral and the question of its convergence leads to the grade restriction rule concerning branes near the phase boundaries. We find expressions in various phases including the large volume formula in which a characteristic class called the Gamma class shows up. The two sphere partition function factorizes into two hemispheres glued by inverse to the annulus. The result can also be written in a form familiar in mirror symmetry, and suggests a way to find explicit mirror correspondence between branes. -
Exact results for boundaries and domain walls in 2d supersymmetric theories
Takuya Okuda University of Tokyo
PIRSA:13100115We apply supersymmetric localization to N=(2,2) gauged linear sigma models on a hemisphere, with boundary conditions, i.e., D-branes, preserving B-type supersymmetries. We explain how to compute the hemisphere partition function for each object in the derived category of equivariant coherent sheaves, and argue that it depends only on its K theory class. The hemisphere partition function computes exactly the central charge of the D-brane, completing the well-known formula obtained by an anomaly inflow argument. We also formulate supersymmetric domain walls as D-branes in the product of two theories. We exhibit domain walls that realize the sl(2) affine Hecke algebra. Based on arXiv:1308.2217. -
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Hybrid conformal field theories
PIRSA:13100114I will discuss a class of limiting points in the moduli space of d=2 (2,2) superconformal field theories. These SCFTs arise as IR limits of "hybrid" UV theories constructed as a fibration of a Landau-Ginzburg theory over a base Kaehler geometry. A significant generalization of Landau-Ginzburg and large radius geometric limit points, the hybrid theories can be used to probe general features of (2,2) and (0,2) SCFT moduli spaces. -
Some simple extensions of Mathieu Moonshine
Shamit Kachru Stanford University
PIRSA:13100112Mathieu Moonshine is a striking and unexpected relationship between the sporadic simple finite group M24 and a special Jacobi form, the elliptic genus, which arises naturally in studies of nonlinear sigma models with K3 target. In this talk, we first discuss its predecessor (Monstrous Moonshine), then discuss the current evidence in favor of Mathieu Moonshine. We also discuss extensions of this story involving `second quantized mirror symmetry,' relating heterotic strings on K3 to type II strings on Calabi-Yau threefolds. -
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3D Digital Holographic Interferometry: Applications in Biomedicine
PIRSA:13080047Digital Holographic Interferometry (DHI) plays an important role in the evaluation of object static and dynamic displacements. The state of the art research on this technique is such that it is being used to solve problems in a wide variety of disciplines, from basic Physics to engineering and even social sciences. This invited plenary talk will deal with specific applications in some biomedical objects, even showing preliminary results using Electron Holography. -
Atomic Physics in the Era of Control: What every physicist should know about the 2012 Physics Nobel Prize
Wes Campbell University of California, Los Angeles
PIRSA:13080042To say that atomic, molecular, and optical (AMO) physics underwent a revival in the 80s and 90s is to acknowledge that it was in need of reviving. Prior to this rebirth, high-quality research was being done in many labs, but it was primarily passive with respect to atomic motion. The demonstration of laser cooling in 1978 ushered in a new era where the full quantum states (internal and external) of atoms would be precisely controlled in the following decades. This control has essentially given today’s AMO physicist the power to “realize the gedanken” and build experiments that exploit quantum mechanics to perform computations, simulations, and measurements with tremendous speed and precision. I will discuss some of the current challenges and potential of this exciting time in the field of AMO physics through the lens of a case study of some of the work of this year’s Nobel Laureates, Dave Wineland and Serge Haroche. -
The impact of the Atmosphere on space-bound Vehicles
PIRSA:13080046When rockets and space-bound vehicles are fired into space, they have to deal with turbulence, winds and waves in the Earth's atmosphere. Different height regimes cause different problems. In the lower regions (0 to 20 km altitude), winds and turbulence are major issues, whereas above 50 km altitude, large atmospheric waves have serious importance on safe passage. Similar issues arise on re-entry. In this talk, I will discuss the ways in which these atmospheric phenomena manifest themselves, and how they are best mitigated. One example of particular significance will be the Space Shuttle Columbia disaster, for which I consulted with NASA in respect to possible atmospheric influences. I will also describe some of the instrumentation used to measure these phenomena. -
Impact cratering and the evolution of planetary surfaces in the solar system – The Chicxulub impact
PIRSA:13080041Impacts of asteroid and comets constitute major geologic processes shaping the surfaces and evolution of planetary bodies. Impacts produce deep transient cavities, with excavation to deep crustal levels, fragmentation, and removal of large rock volumes. Formation of complex craters involves high pressures and temperatures resulting in intense deformation, fracturing and melting. Here, we analyze the crater-forming impacts and their effects on the Earth´s climate, environment and life-support systems, in relation to the Cretaceous/Paleogene (K/Pg) boundary. The boundary represents one of the major extinction events in the Phanerozoic, which affected about 75 % of species. It is marked by a clay layer globally distributed that is characterized by anomalous contents of iridium and platinum group elements, marking the occurrence of a large bolide impact. Studies have examined the age, stratigraphic correlations and composition of the boundary layer, establishing a genetic association to the Chicxulub impact in the Yucatan peninsula in the Gulf of Mexico. The Chicxulub crater is a ~200 km diameter structure with peak ring and multi-ring morphology. Impact generated a transient cavity some 20-25 km deep resulting in intense deformation and shaking, which is recorded in the breccias and debris flow deposits in the Gulf of Mexico and Caribbean Sea area. Impact was on a shallow carbonate platform and resulted in huge tsunamis and in injection of CO2 and sulfur components into the atmosphere. Effects of impacts in the environment and climate of the Earth have been intensely investigated, mainly in relation to the mass extinction, where the affectation in the evolution patterns was profound and long-lasting. Effects of the K/Pg impact on the ecosystems extended for a long period of several millions of years. The disappearance of large numbers of species including complete groups severely affected the biodiversity and ecosystem composition in the marine and continental realms.