DSpace Collection:http://hdl.handle.net/2289/32172024-03-19T22:04:49Z2024-03-19T22:04:49ZStatistical Physics of Active ParticlesSantra, Ionhttp://hdl.handle.net/2289/81682023-11-01T11:10:40Z2023-07-19T00:00:00ZTitle: Statistical Physics of Active Particles
Authors: Santra, Ion
Description: Restricted Access2023-07-19T00:00:00ZQuantum Fields from Casual OrderMathur, Abhishekhttp://hdl.handle.net/2289/80542023-03-01T06:01:00Z2023-02-01T00:00:00ZTitle: Quantum Fields from Casual Order
Authors: Mathur, Abhishek
Abstract: Quantum Field Theory (QFT) in curved spacetime describes physical phenomena in a regime where quantum fields interact with the classical gravitational field. These conditions are generally satisfied either in the vicinity of a black hole or in the post Planckian very early universe. The standard approach to QFT relies heavily on the Poincare symmetry of Minkowski spacetime as a guide to a particular choice of mode expansion and therefore a preferred choice of vacuum. In contrast, in a generic curved spacetime which does not have any symmetry, the choice of mode expansion and hence the vacuum is arbitrary. This suggests that the notion of vacuum and particles is subsidiary. This is the approach taken in algebraic QFT (AQFT), where the primary role is played by the algebra of observables and the choice of state, which is primarily defined as a complex function on this algebra, is relegated to a choice of the representation of this algebra, and is therefore not unique. It is natural to ask if there exists an alternative formulation of the QFT vacuum which is inherently covariant. One such formalism was developed by Sorkin [1] and Johnston [2] called the Sorkin-Johnston (SJ) vacuum. In this thesis we will explore various aspects of the SJ vacuum both in the continuumand in the causal set theory. QFT also plays an important role in understanding the entropy of black holes and other horizons. Entanglement entropy of quantum fields has been proposed as a candidate for these entropies. The standard formulation of the entanglement entropy is given by the von Neumann entropy formula, which requires the QFT states to be defined on a Cauchy hypersurface and is therefore dependent on the choice of the hypersurface. Sorkin, in his 2014 paper [3], proposed a spacetime formulation of the entanglement entropy, which is covariant.
Description: Restricted Access2023-02-01T00:00:00ZNon-equilibrium behavior in self-driven systemsDas, Santanuhttp://hdl.handle.net/2289/79342022-05-10T09:19:13Z2021-01-20T00:00:00ZTitle: Non-equilibrium behavior in self-driven systems
Authors: Das, Santanu
Abstract: The primary objective of statistical physics is to explain the behaviors of a macroscopic
system by starting its description from the microscopic level. Undoubtedly,
the most successful branch of this subject is its equilibrium counterpart, which is
quite old and well-established with its foundations and formalisms. It is well known
that the equilibrium of a macroscopic system is ensured by the principle of the
detailed balance. It states that the net current between any two points in the con-
guration space is zero if the system is in equilibrium. If the net current is non-zero
in the same case, then the system is in non-equilibrium for which there is no widelyaccepted
framework like equilibrium exist in the literature. Besides that, the variety
of non-equilibrium systems and the richness of emergent phenomena therein makes
the subject interest growing in time.
Description: Open Access2021-01-20T00:00:00ZTransport, Clustering and Chemical Kinetics of cell surface molecules influenced by actomyosin cortexHossein, Raj S Khttp://hdl.handle.net/2289/79162022-04-01T11:09:14Z2022-03-01T00:00:00ZTitle: Transport, Clustering and Chemical Kinetics of cell surface molecules influenced by actomyosin cortex
Authors: Hossein, Raj S K
Description: Restricted access2022-03-01T00:00:00Z