Division of Physical and Mathematical Sciences: Recent submissions
Now showing items 141-160 of 900
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Positivity preservers forbidden to operate on diagonal blocks
The question of which functions acting entrywise preserve positive semidefiniteness has a long history, beginning with the Schur product theorem [Crelle 1911], which implies that absolutely monotonic functions (i.e., ... -
Dynamo Action in Rotating and Shearing Flows
Magnetic fields are omnipresent in universe. They play important role in the formation of stars, galaxies and the accretion onto compact objects and the collimation of the relativistic jets of radio galaxies. It is intriguing ... -
On certain invariant measures for correspondences, their analysis, and an application to recurrence
The aim of this dissertation is to analyse a certain class of dynamically interesting mea- sures arising in holomorphic dynamics that goes beyond the classical framework of maps. We study measures associated with semigroups ... -
Hermitian Metrics and Singular Riemann Surface Foliations
The main aim of this thesis is to understand curvature properties of a given hermitian metric by restricting it to the leaves of a suitable singular Riemann surface foliation. We will specifically consider the complete ... -
Nodal sets of random functions
This thesis is devoted to the study of nodal sets of random functions. The random functions and the specific aspect of their nodalset that we study fall into two broad categories: nodal component count of Gaussian Laplace ... -
Asymptotic Analysis of Multi-scale, Multi-loop Feynman Diagrams
It is very challenging to solve multi-scale, multi-loop Feynman diagrams analytically. The presence of different kinematic scales makes the computation of Feynman diagrams very difficult, sometimes impossible to get the ... -
Multiscale Simulation of Nucleic Acid Nanostructures
Nucleic acids, namely DNA and RNA, are arguably the most studied biological molecules. Utilizing the key properties of nucleic acids, such as their persistence lengths and Watson-Crick base-pairing complementarity, ... -
Role of gamma oscillations in processing of natural stimuli
Gamma oscillations (~30-80 Hz) are a prominent signature of electrophysiological signals recorded from the brain with proposed roles in various cognitive functions such as attention and visual perception. Although gamma ... -
On the Geometry and Operator Theory of the Bidisc and the Symmetrized Bidisc
This work is concerned with the geometric and operator theoretic aspects of the bidisc and the symmetrized bidisc. First we have focused on the geometry of these two do- mains. The symmetrized bidisc, a non-homogeneous ... -
On the electrical transport of weak topological insulators and Weyl semimetals
Topological insulators have garnered enormous amount of attention owing to their unique topological properties. The surface states protected by the topology of the system hold limitless potentials including topological ... -
Tuning of electrical and magnetic properties in nanocomposites of conductive LaNiO3 and transition metal oxides
The discovery of new composites by integrating materials of different physical properties with optimal control is of immense interest to researchers at present. Today, there are several composites being used for several ... -
The role of quantum fluctuations in the t-J model: Implications for cuprate superconductors
The physics of strongly correlated electron systems is among the central problems of condensed matter physics. One of the outstanding problems in this category is that of the high-Tc superconductivity obtained by doping ... -
Observational Constraints on Global 21-cm Signal from the Epoch of Reionization
One of the most promising probes of Cosmic Dawn (CD) and Epoch of Reionization (EoR) is the rest-frame global 21-cm signal of neutral hydrogen (HI) produced by the intergalactic medium (IGM) prior to the end of the EoR ... -
Quantum transport in Graphene Moire Superlattice and p-n junction
The discovery of graphene has revolutionized the field of mesoscopic condensed matter physics. It has started a new field of van-der Waals heterostructure in which different two-dimensional materials including graphene can ... -
Analytical Mellin-Barnes techniques with applications to two-loop SU(3) chiral perturbation theory and QED at higher loops
The present era is one of precision in particle physics. To account for the lacunae in the otherwise successful Standard Model, observables are calculated to high precision in various theoretical models, which are then ... -
Electronic transport in low dimensional LaAlO3/SrTiO3 heterointerface
The large variety of phenomena exhibited by the interface between two band-insulators LaAlO3 and SrTiO3 has attracted intense research activity in recent years.The interplay of different symmetries, viz. point group ... -
Influence of local structure and network connectivity on the electrical switching of some Te-based chalcogenide glasses
Chalcogenide glass (ChG) materials have gained wide attention because of their applications in phase change non-volatile memories (PC-RAM), optical rewritable disks (CD-RW and DVD-RW), infrared detection and thermal imaging. ... -
Studying bubbles in liquid He4 containing single and many electrons
Helium is an inert element with fully occupied orbitals and is a super fluid at low temperatures. An electron close to the surface of liquid Helium faces a long range attraction due to the finite polarizability of the ... -
Engineering topological surface states through structural control, electrostatic gating and superconducting proximity effects
Three dimensional topological insulators are materials characterized by a gapped insulating bulk and gapless metallic states on the sample surface. This unique be- havior arises out of the non-trivial topology of the ... -
Textured Gate Thin Film Transistors and Circuits
Reliable, high performance integrated circuits based on thin film transistors (TFTs) on flexible substrates have a lot of advantages, especially in applications like flexible displays, spherical image sensors, wearable ...