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Curvature in terms of entanglement

Achim Kempf University of Waterloo
December 12, 2013

PIRSA:13120064
Quantum Gravity
holographic path to the turbulent side of gravity
- Adam Brown Stanford University
- Stephen Green University of Nottingham
December 12, 2013

PIRSA:13120066
Cosmology
Partially Massless Gravity
December 11, 2013

PIRSA:13120005
Cosmology
Rebuilding Mathematics on a Quantum Logical Foundation

Richard deJonghe University of Illinois at Chicago
December 10, 2013

PIRSA:13120060
Quantum Foundations
Consistency of Massive Gravity

Lavinia Heisenberg ETH Zurich
December 10, 2013

PIRSA:13120061
Cosmology
(0,2) Trialities

Abhijit Gadde Stony Brook University
December 10, 2013

PIRSA:13120062
Quantum Fields and Strings
Compactifying de Sitter

Alex Dahlen Princeton University
December 10, 2013

PIRSA:13120049
Cosmology
No GUTs, All Glory: Charge Quantization and the Standard Model from Nonlinear Sigma Models

John Kehayias University of Tokyo
December 06, 2013

PIRSA:13120056
Particle Physics
Symmetry Enriched Quantum Spin Ices On the Pyrochlore Lattice

Gang Chen Fudan University
December 06, 2013

PIRSA:13120055
Condensed Matter
Calculating the free energy of antimicrobial peptide (HHC-36) dimerization in bulk

shaqa vafa University of Guelph

December 05, 2013

PIRSA:13120043
Ab initio insight in supercooled water

John Tatini Titantah Western University

December 05, 2013

PIRSA:13120042
Budding transition of a self-avoiding polymer confined by a soft membrane adhering onto a flat wall

Yu-Cheng Su University of Waterloo

December 05, 2013

PIRSA:13120041

Curvature in terms of entanglement

Achim Kempf University of Waterloo
December 12, 2013

PIRSA:13120064
Quantum Gravity
The entanglement of the quantum field theoretic vacuum state is affected by curvature. I ask if or under which conditions the curvature of spacetime can be expressed entirely in terms of the spatial entanglement structure of the vacuum. This would open up the prospect that general relativity could be formulated in quantum theoretic terms, which should then be helpful for studies in quantum gravity.
holographic path to the turbulent side of gravity
- Adam Brown Stanford University
- Stephen Green University of Nottingham
December 12, 2013

PIRSA:13120066
Cosmology
We study the dynamics of a 2+1 dimensional relativistic viscous conformal fluid in Minkowski spacetime. Such fluid solutions arise as duals, under the "gravity/fluid correspondence", to 3+1 dimensional asymptotically anti-de Sitter (AAdS) black brane solutions to the Einstein equation. We examine stability properties of shear flows, which correspond to hydrodynamic quasinormal modes of the black brane. We find that, for sufficiently high Reynolds number, the solution undergoes an inverse turbulent cascade to long wavelength modes. We then map this fluid solution, via the gravity/fluid duality, into a bulk metric. This suggests a new and interesting feature of the behavior of perturbed AAdS black holes and black branes, which is not readily captured by a standard quasinormal mode analysis. Namely, for sufficiently large perturbed black objects (with long-lived quasinormal modes), nonlinear effects transfer energy from short to long wavelength modes via a turbulent cascade within the metric perturbation. As long wavelength modes have slower decay, this lengthens the overall lifetime of the perturbation. We also discuss various implications of this behavior, including expectations for higher dimensions, and the possibility of predicting turbulence in more general gravitational scenarios."
Partially Massless Gravity
December 11, 2013

PIRSA:13120005
Cosmology
On de Sitter space, there exists a special value for the mass of a graviton for which the linear theory propagates 4 rather than 5 degrees of freedom. If a fully non-linear version of the theory exists and can be coupled to known matter, it would have interesting properties and could solve the cosmological constant problem. I will describe evidence for and obstructions to the existence of such a theory.
Rebuilding Mathematics on a Quantum Logical Foundation

Richard deJonghe University of Illinois at Chicago
December 10, 2013

PIRSA:13120060
Quantum Foundations
It is not unnatural to expect that difficulties lying at the foundations of quantum mechanics can only be resolved by literally going back and rethinking the quantum theory from first principles (namely, the principles of logic). In this talk, I will present a first-order quantum logic which generalizes the propositional quatum logic originated by Birkhoff and von Neumann as well as the standard classical predicate logic used in the development of virtually all of modern mathematics. I will then use this quantum logic to begin to build the foundations of a new ``quantum mathematics'' --- in particular a quantum set theory and a quantum arithmetic --- which has the potential to provide a completely new mathematical framework in which to develop the theory of quantum
mechanics.
Consistency of Massive Gravity

Lavinia Heisenberg ETH Zurich
December 10, 2013

PIRSA:13120061
Cosmology
Recently there has been a successful non-linear covariant ghost-free generalization of Fierz-Pauli massive gravity theory, the dRGT theory. I will explore the cosmology in the decoupling limit of this theory. Furthermore, I will construct a Proxy theory to dRGT from the decoupling limit and study the cosmology there as well and compare the results. Finally, I will discuss the quantum consistency of the theory.
(0,2) Trialities

Abhijit Gadde Stony Brook University
December 10, 2013

PIRSA:13120062
Quantum Fields and Strings
Motivated by the connection between 4-manifolds and 2d N=(0,2) theories, we study the dynamics of a fairly large class of 2d N=(0,2) gauge theories. We see that physics of such theories is very rich, much as the physics of 4d N=1 theories. We discover a new type of duality that is very reminiscent of the 4d Seiberg duality. Surprisingly, the new 2d duality is an operation of order three. We study the low energy physics and use elliptic genus to detect dynamical supersymmetry breaking.
Compactifying de Sitter

Alex Dahlen Princeton University
December 10, 2013

PIRSA:13120049
Cosmology
TBA
No GUTs, All Glory: Charge Quantization and the Standard Model from Nonlinear Sigma Models

John Kehayias University of Tokyo
December 06, 2013

PIRSA:13120056
Particle Physics
I will present recent and ongoing work in collaboration with Tsutomu Yanagida and Simeon Hellerman (arXiv:1309.0692 and 1312.xxxx) on a new way to obtain charge quantization, without a GUT or monopole solution. In the CP^1 model, SU(2)_G/U(1)_H, consistency conditions for a charged field and its transformation properties over the entire group manifold lead to a charge quantization condition. By gauging the U(1)_H and identifying it with hypercharge, we find charge quantization in the SM without a monopole or GUT, purely from the structure and dynamics of the nonlinear sigma model. This is easily extended to CP^2 and general CP^k models. Phenomenologically, the CP^1 model has a fractionally charged stable Nambu-Goldstone boson (NGB), which has intriguing applications to nuclear physics and dark matter. The CP^2 model has the Higgs as the NGB. With some additional minor assumptions, anomaly freedom then leads to the matter content of a generation in the SM.
Symmetry Enriched Quantum Spin Ices On the Pyrochlore Lattice

Gang Chen Fudan University
December 06, 2013

PIRSA:13120055
Condensed Matter
Quantum spin liquid (QSL) is an exotic phase of matter and provides an interesting example of emergent non-locality. Even though many materials have been proposed as candidates for QSLs, there is no direct confirmation of QSLs in any of these systems. Quantum spin ice (QSI) is a physical realization of U(1) QSLs on the pyrochlore lattice. We consider a class of electron systems in which dipolar-octupolar Kramers doublets arise on the pyrochlore lattice. In the localized limit, the Kramers doublets are described by the effective spin 1/2 pseudospins. The most general nearest-neighbor exchange model between these pseudospins is the XYZ model. We show that this XYZ model exhibit two distinct symmetry enriched QSI phases, that we dub dipolar QSI and octupolar QSI. This XYZ model is absent from the notorious sign problem for a quantum Monte Carlo simmulation. We also discuss the potential relevance to real material systems.
Calculating the free energy of antimicrobial peptide (HHC-36) dimerization in bulk

shaqa vafa University of Guelph

December 05, 2013

PIRSA:13120043

The increasing demand for antibiotics has contributed to the investigation of possible novel antibiotics by many researchers. For this purpose experimental and theoretical studies have been carried out to draw scientists' attention to antimicrobial peptides and their interaction with the surface of bacterial membranes. Their ability to disrupt the functioning of bacterial membranes has been probed from different perspectives. The most desirable antimicrobial peptides are those which do not harm plant or animals' membranes but which disrupt bacterial membranes. It has been found that some cationic antimicrobial peptides (CAPs) satisfy these requirements. CAPs interacting with the outer membrane of gram-negative bacteria and the membrane of gram-positive bacteria have been studied recently.We conduct a Molecular Dynamics simulation study of peptide-peptide interactions in physiological solutions and investigate the mechanism of CAPs aggregation since aggregation of the peptides could precede their interaction with the membrane. Different algorithms are applied to calculate the potential mean force of the aggregation process of peptides to select the most efficient one. Also we have run CD spectroscopy and calorimetry experiments to predict the structure of the peptide and measure the peptide-peptide binding enthalpy and compared these results with our simulation data. The particular CAP studied is HHC-36 a peptide selected by high throughput screening (A. Cherkasov et al ACS Chem. Biol. 2009 4 (1) pp 6574) (M. Kazemzadeh-Narbat et al Biomed. Mater. Res. Part B 2012 5 pp1344-1352) (M. Ma et al Biomed. Mater. Res. Part A 2012 2 pp278-185) which has nine amino acid residues and charge +5.
Ab initio insight in supercooled water

John Tatini Titantah Western University

December 05, 2013

PIRSA:13120042

As an extension to previous ab initio studies on water [12] we present 400 psBorn-Oppenheimer ab initio Molecular dynamics study on water at deep supercooled temperatures (down to 220 K) and confirm a crossover from a fragile to strongliquid around the Widom line. This crossover is accompanied by the passage from relatively weaker hydrogen bonds in the dominantly high density liquid (HDL) at high temperatures to strong hydrogen bond in dominantly low density liquid (LDL). This crossover is accompanied by a maximum in the excess specific heat at constant volume and may lend further support to the existence of a liquid-liquid critical point (LLCP) in supercooled water as was predicted by Peter Poole and collaborators using ST2 water model[3].References[1] J. T. Titantah and M. Karttunen Long-Time Correlations and Hydrophobe-Modified Hydrogen-Bonding Dynamics in Hydrophobic Hydration. J. Am. Chem. Soc. 134 9362 (2012)[2] J. T. Titantah and M. Karttunen Water dynamics: Relation between hydrogen bond bifurcations molecular jumps local density & hydrophobicity. Sci. Rep. 3 2991 (2013)[3] Poole P. H. Sciortino F. Essmann U. & Stanley H. E. Phase behaviour of metastable water. Nature 360 324328 (1992)
Budding transition of a self-avoiding polymer confined by a soft membrane adhering onto a flat wall

Yu-Cheng Su University of Waterloo

December 05, 2013

PIRSA:13120041

Monte Carlo simulation is used to study the structural properties of the system consisting of a self-avoiding polymer chain confined between a fluid membrane and a flat hard surface. As the adhesion between the soft membrane and the hard-wall surface increases the polymer is subject to a strong confinement; a pancake-shaped polymer conformation state eventually yields to a bud state through an abrupt first-order phase transition. We explore the scaling behavior of the physical properties of the system as functions of the polymers size the membranes surface tension and the adhesion energy for both pancake and bud states in terms of Monte Carlo data and analytic scaling theories.

Title	Date	Collection	Type	Info
Curvature in terms of entanglement	2013‑12‑12	Quantum Gravity	Scientific Series	View details
holographic path to the turbulent side of gravity	2013‑12‑12	Cosmology and Gravitation	Scientific Series	View details
Partially Massless Gravity	2013‑12‑11	Colloquium	Scientific Series	View details
Rebuilding Mathematics on a Quantum Logical Foundation	2013‑12‑10	Quantum Foundations	Scientific Series	View details
Consistency of Massive Gravity	2013‑12‑10	Cosmology and Gravitation	Scientific Series	View details
(0,2) Trialities	2013‑12‑10	Quantum Fields and Strings	Scientific Series	View details
Compactifying de Sitter	2013‑12‑10	Cosmology and Gravitation	Scientific Series	View details
No GUTs, All Glory: Charge Quantization and the Standard Model from Nonlinear Sigma Models	2013‑12‑06	Particle Physics	Scientific Series	View details
Symmetry Enriched Quantum Spin Ices On the Pyrochlore Lattice	2013‑12‑06	Quantum Matter	Scientific Series	View details
Calculating the free energy of antimicrobial peptide (HHC-36) dimerization in bulk	2013‑12‑05	Waterloo Soft Matter Theory	Conference	View details
Ab initio insight in supercooled water	2013‑12‑05	Waterloo Soft Matter Theory	Conference	View details
Budding transition of a self-avoiding polymer confined by a soft membrane adhering onto a flat wall	2013‑12‑05	Waterloo Soft Matter Theory	Conference	View details

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