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Chennai, India

Chennai Mathematical Institute is a research and education institute in Chennai, India. It was founded by the SPIC Science Foundation in 1989, and offers undergraduate as well as postgraduate programmes in Physics, Mathematics and Computer Science, besides its key strength in the form of high-end research in Mathematics. CMI is noted for its research in the field of algebraic geometry, in particular in the area of moduli of bundles.CMI was earlier located in T. Nagar in the heart of Chennai in an office complex. It moved to a new 5-acre campus in Siruseri in October 2005.In December 2006, CMI was recognized as a university under Section 3 of the UGC Act 1956, making it a deemed university. Until then, the teaching program was offered in association with Bhoj Open University, as it offered more flexibility. Wikipedia.

Hassan S.R.,Chennai Mathematical Institute | Senechal D.,Universite de Sherbrooke
Physical Review Letters | Year: 2013

The question of the existence of a spin liquid state in the half-filled Hubbard model on the honeycomb (also known as graphene) lattice is revisited. The variational cluster approximation, the cluster dynamical mean field theory, and the cluster dynamical impurity approximation are applied to various cluster systems. Assuming that the spin liquid phase coincides with the Mott insulating phase in this nonfrustrated system, we find that the Mott transition is preempted by a magnetic transition occurring at a lower value of the interaction U, and therefore the spin liquid phase does not occur. This conclusion is obtained using clusters with two bath orbitals connected to each boundary cluster site. We argue that using a single bath orbital per boundary site is insufficient and leads to the erroneous conclusion that the system is gapped for all nonzero values of U. © 2013 American Physical Society.

Narayan K.,Chennai Mathematical Institute
Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics | Year: 2013

Following Narayan (2012) [4] and Narayan et al. (2013) [8], we study non-conformal brane plane wave backgrounds dual to strongly coupled gauge theories with constant energy flux and holographic entanglement entropy for strip subsystems in them. We find that for the strip direction along the direction of the energy flux, the finite cutoff-independent part of entanglement entropy can be estimated in terms of a dimensionless combination of the energy density and the strip dimensions, alongwith an effective scale-dependent number of degrees of freedom. For the strip orthogonal to the flux direction, there are indications of phase transitions. We also briefly discuss NS5-brane backgrounds corresponding to plane wave states in little string theories. © 2013 Elsevier B.V.

Ponmurugan M.,Chennai Mathematical Institute
Physical Review E - Statistical, Nonlinear, and Soft Matter Physics | Year: 2010

It has been shown recently that the Jarzynski equality is generalized under nonequilibrium feedback control. The presence of feedback control in physical systems should modify both the Jarzynski equality and the detailed fluctuation theorem. However, the generalized Jarzynski equality under forward feedback control has been proved by considering that the physical systems under feedback control should locally satisfy the detailed fluctuation theorem. We use the same formalism and derive the generalized detailed fluctuation theorem for nonequilibrium driven systems under feedback control. We find that the feedback control in a physical system should preserve the detailed fluctuation theorem if the system has the same feedback information measure in forward and reverse directions. © 2010 The American Physical Society.

Chandrashekar C.M.,Chennai Mathematical Institute
Physical Review A - Atomic, Molecular, and Optical Physics | Year: 2011

We present an approach to induce localization of a Bose-Einstein condensate in a one-dimensional lattice under the influence of unitary quantum-walk evolution using disordered quantum coin operation. We introduce a discrete-time quantum-walk model in which the interference effect is modified to diffuse or strongly localize the probability distribution of the particle by assigning a different set of coin parameters picked randomly for each step of the walk, respectively. Spatial localization of the particle or state is explained by comparing the variance of the probability distribution of the quantum walk in position space using disordered coin operation to that of the walk using an identical coin operation for each step. Due to the high degree of control over quantum coin operation and most of the system parameters, ultracold atoms in an optical lattice offer opportunities to implement a disordered quantum walk that is unitary and induces localization. Here we present a scheme to use a Bose-Einstein condensate that can be evolved to the superposition of its internal states in an optical lattice and control the dynamics of atoms to observe localization. This approach can be adopted to any other physical system in which controlled disordered quantum walk can be implemented. © 2011 American Physical Society.

Ma E.,University of California at Riverside | Srivastava R.,Chennai Mathematical Institute
Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics | Year: 2015

Many studies have been made on extensions of the standard model with B-L gauge symmetry. The addition of three singlet (right-handed) neutrinos renders it anomaly-free. It has always been assumed that the spontaneous breaking of B-L is accomplished by a singlet scalar field carrying two units of B-L charge. This results in a very natural implementation of the Majorana seesaw mechanism for neutrinos. However, there exists in fact another simple anomaly-free solution which allows Dirac or inverse seesaw neutrino masses. We show for the first time these new possibilities and discuss an application to neutrino mixing with S3 flavor symmetry. © 2015 The Authors.

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