Triangle Seminars
Tuesday, 9 Nov 2010
Evolution as an information dynamic system
Roman Belavkin
(Middlesex University)
Abstract:
I will speak about a new research project called 'Evolution as an information dynamic system', which involves collaboration between four universities in the United Kingdom. This is a three year project started this year, 2010, and its aim is to develop new understanding of information dynamics in evolution and biology. In particular, we are going to derive new optimality conditions for some evolutionary operators, such as mutation and recombination. Evolutionary states will be represented by probability measures on the space of genetic sequences, and different operators produce different evolution of the states. We define the optimality conditions for evolution based on the maximisation of utility (or fitness) of information principle. The optimal evolution in this sense achieves the shortest 'information distance', and it can be different from an evolution optimal in another sense, such as the shortest convergence time. We argue that the former achieves a better adaptation of organisms living in a dynam
ic environment. I will present several early results related to the optimisation of mutation rate parameter. I will review these results in the light of the classical theories of adaptation (e.g. Fisher's geometric model) and error threshold. Then I will outline some future theoretical and experimental work of the project.
I will speak about a new research project called 'Evolution as an information dynamic system', which involves collaboration between four universities in the United Kingdom. This is a three year project started this year, 2010, and its aim is to develop new understanding of information dynamics in evolution and biology. In particular, we are going to derive new optimality conditions for some evolutionary operators, such as mutation and recombination. Evolutionary states will be represented by probability measures on the space of genetic sequences, and different operators produce different evolution of the states. We define the optimality conditions for evolution based on the maximisation of utility (or fitness) of information principle. The optimal evolution in this sense achieves the shortest 'information distance', and it can be different from an evolution optimal in another sense, such as the shortest convergence time. We argue that the former achieves a better adaptation of organisms living in a dynam
ic environment. I will present several early results related to the optimisation of mutation rate parameter. I will review these results in the light of the classical theories of adaptation (e.g. Fisher's geometric model) and error threshold. Then I will outline some future theoretical and experimental work of the project.
Posted by: KCL
Wednesday, 10 Nov 2010
Y-system for AdS/CFT
📍 London
Nikolay Gromov
(King's)
Abstract:
The Y-system, originating from integrability, is a tool
describing the exact spectrum in 4D N=4 Super-Yang-Mills theory in
a planar limit. We describe the construction and discuss predictions
and tests for weak, strong and intermediate couplings.
The Y-system, originating from integrability, is a tool
describing the exact spectrum in 4D N=4 Super-Yang-Mills theory in
a planar limit. We describe the construction and discuss predictions
and tests for weak, strong and intermediate couplings.
Posted by: KCL
Supersymmetric 3-algebra theories in 6 dimensions
Costis Papageorgakis
(KCL)
Abstract:
Using 3-algebras we obtain a nonabelian system of equations that furnish a representation of the (2,0)-supersymmetric tensor multiplet. The on-shell conditions are quite restrictive so that the system can be reduced to five-dimensional super-Yang-Mills theory along with six-dimensional abelian (2,0) tensor multiplets. Possible applications to D4-branes and M5-branes are discussed.
Using 3-algebras we obtain a nonabelian system of equations that furnish a representation of the (2,0)-supersymmetric tensor multiplet. The on-shell conditions are quite restrictive so that the system can be reduced to five-dimensional super-Yang-Mills theory along with six-dimensional abelian (2,0) tensor multiplets. Possible applications to D4-branes and M5-branes are discussed.
Posted by: IC
Thursday, 11 Nov 2010
Dualities for scattering amplitudes in maximally supersymmetric Yang-Mills theory
Gregory Korchemsky
(Saclay)
Abstract:
I will review a recent progress in computing scattering amplitudes in N=4 SYM theory and explain the recently found duality between MHV gluon scattering amplitudes and correlation functions of half-BPS protected operators in the limit where
the positions of the adjacent operators become light-like separated.
I will review a recent progress in computing scattering amplitudes in N=4 SYM theory and explain the recently found duality between MHV gluon scattering amplitudes and correlation functions of half-BPS protected operators in the limit where
the positions of the adjacent operators become light-like separated.
Posted by: QMW
Friday, 12 Nov 2010
Enthalpy, Areas and Inequalities for Black Holes in Gauged Supergravities
Chris Pope
(Texas / Cambridge)
Abstract:
Various aspects of the geometry and the thermodynamics of black holes in gauged supergravities are explored. In such theories, where the gauge coupling or the cosmological constant can be thought of as an integration constant arising from a higher-dimensional origin, it becomes appropriate to think of it as an additional thermodynamic variable associated with a pressure. The conjugate variable defines a volume for the black hole,
although its geometric interpretation becomes quite subtle if the black
hole is rotating. Further geometric properties of the black holes are
also explored, including an intriguing universal structure for the product
of the horizon areas, which is suggestive of a possible dual field theory
explanation for the microscopic entropy. Isoperimetric and hoop
inequalities are also discussed.
Various aspects of the geometry and the thermodynamics of black holes in gauged supergravities are explored. In such theories, where the gauge coupling or the cosmological constant can be thought of as an integration constant arising from a higher-dimensional origin, it becomes appropriate to think of it as an additional thermodynamic variable associated with a pressure. The conjugate variable defines a volume for the black hole,
although its geometric interpretation becomes quite subtle if the black
hole is rotating. Further geometric properties of the black holes are
also explored, including an intriguing universal structure for the product
of the horizon areas, which is suggestive of a possible dual field theory
explanation for the microscopic entropy. Isoperimetric and hoop
inequalities are also discussed.
Posted by: IC