A5026114820- Particle physics theoretical and experimental studies
- Black Holes and Theoretical Physics
- Cosmology and Gravitation Theories
- Noncommutative and Quantum Gravity Theories
- Quantum Mechanics and Applications
- Quantum Mechanics and Non-Hermitian Physics
- Quantum Chromodynamics and Particle Interactions
- Physics of Superconductivity and Magnetism
- Quantum Information and Cryptography
- Quantum optics and atomic interactions
- Photonic and Optical Devices
- Optical Network Technologies
- Neutrino Physics Research
- Advanced Fiber Optic Sensors
- Quantum chaos and dynamical systems
- Advanced Fiber Laser Technologies
- Photonic Crystal and Fiber Optics
- Dark Matter and Cosmic Phenomena
- Quantum and electron transport phenomena
- Advanced Thermodynamics and Statistical Mechanics
- Nonlinear Dynamics and Pattern Formation
- High-Energy Particle Collisions Research
- Semiconductor Lasers and Optical Devices
- Cold Atom Physics and Bose-Einstein Condensates
- Laser-Matter Interactions and Applications
King's College London
2016-2025
Teerthanker Mahaveer University
2023
Mahaveer Academy of Technology and Science University
2023
Imperial College London
1972-2021
Czech Technical University in Prague
2021
Universitat de València
2021
Centre de Recherche en Astronomie Astrophysique et Géophysique
2021
University College London
1992-2021
University of Calcutta
1996-2014
University of London
1992-2012
We investigate the rate at which two initially decoupled quantum kicked tops become entangled upon introduction of an interaction between them. find that entanglement eventually increases linearly in time. Moreover, we this linear increase is itself a function sum positive Lyapunov exponents when averaged over initial points drawn from classical distributions corresponding to product state. The measure used allows us identify with sensitive dependence on conditions.
The MoEDAL experiment at Point 8 of the LHC ring is seventh and newest experiment. It dedicated to search for highly-ionizing particle avatars physics beyond Standard Model, extending significantly discovery horizon LHC. A would have revolutionary implications our fundamental understanding Microcosm. an unconventional largely passive detector comprised largest array Nuclear Track Detector stacks ever deployed accelerator, surrounding intersection region on ring. Another novel feature use...
MoEDAL is designed to identify new physics in the form of long-lived highly ionizing particles produced high-energy LHC collisions. Its arrays plastic nuclear-track detectors and aluminium trapping volumes provide two independent passive detection techniques. We present here results a first search for magnetic monopole production 13 TeV proton-proton collisions using technique, extending previous publication with 8 data during Run 1. A total 222 kg detector samples was exposed forward region...
The MoEDAL experiment is designed to search for magnetic monopoles and other highly-ionising particles produced in high-energy collisions at the LHC. largely passive detector, deployed Interaction Point 8 on LHC ring, relies two dedicated direct detection techniques. first technique based stacks of nucleartrack detectors with surface area ~18m2, sensitive particle ionisation exceeding a high threshold. These are analysed offline by optical scanning microscopes. second trapping charged an...
We develop a method for accurately calculating vacuum decay rates beyond the thin-wall regime in pure scalar field theory at one-loop level of effective action. It accounts radiative effects resulting from quantum corrections to classical bounce, including gradient stemming inhomogeneity bounce background. To achieve this, it is necessary compute not only functional determinant fluctuation operator background but also its derivative evaluated bounce. The former efficiently calculated using...
In this work we consider a phenomenological model for leptogenesis in the context of Standard Model Extension with an axial-like background coupling to fermions that violates both Lorentz and CPT symmetries. The latter is motivated by geometry early Universe involving particular kind torsion, arising from Kalb-Ramond antisymmetric tensor field which appears gravitational multiplet string theory, although do not restrict ourselves framework. It shown can occur even at tree level only one...
$\mathcal{P}\mathcal{T}$-symmetric quantum mechanics began with a study of the Hamiltonian $H={p}^{2}+{x}^{2}(ix{)}^{ϵ}$. A surprising feature this non-Hermitian is that its eigenvalues are discrete, real, and positive when $ϵ\ensuremath{\ge}0$. This paper examines corresponding quantum-field-theoretic $H=\frac{1}{2}(\ensuremath{\nabla}\ensuremath{\phi}{)}^{2}+\frac{1}{2}{\ensuremath{\phi}}^{2}(i\ensuremath{\phi}{)}^{ϵ}$ in $D$-dimensional spacetime, where $\ensuremath{\phi}$ pseudoscalar...
The scalar field theory with potential $V(\varphi)=\textstyle{\frac{1}{2}} m^2\varphi^2-\textstyle{\frac{1}{4}} g\varphi^4$ ($g>0$) is ill defined as a Hermitian but in non-Hermitian $\mathcal{P}\mathcal{T}$-symmetric framework it well defined, and has positive real energy spectrum for the case of spacetime dimension $D=1$. While methods used literature do not easily generalize to quantum theory, this paper path-integral representation $-g\varphi^4$ shown provide unified formulation general...
This paper considers the possibility that, starting from a relativistic Hermitian quantum field theory in ultraviolet (UV) regime, and applying nonperturbative renormalization-group (RG) flow, we arrive at situation where there are infrared (IR) singularities RG flow of couplings. The latter can be resolved by assuming that have phase described related non-Hermitian <a:math xmlns:a="http://www.w3.org/1998/Math/MathML" display="inline"><a:mi mathvariant="script">PT</a:mi></a:math>-symmetric...
The low-lying eigenstates of a system two electrons confined within two-dimensional quantum dot with hard polygonal boundary are obtained by means exact diagonalization. transition from weakly correlated charge distribution for small dots to strongly ``Wigner molecule'' large is studied, and the behavior at crossover determined. In sufficiently dots, recently proposed mapping an effective charge-spin model investigated, found produce correct ordering energy levels give good first...
The t-J model (related to the strong-correlation limit of Hubbard model) is shown be soluble in one dimension using Bethe ansatz. solution holds only when Hamiltonian supersymmetric. ground state presence holes found gapless, and have no magnetization.
The t-J model for strongly correlated electron systems is mapped onto a with generalised permutation operator. For specific value of the ratio t/J this in one space dimension shown to be equivalent that Lai (1974) and can solved by Bethe ansatz. This special point corresponds supersymmetric invariance Hamiltonian.
In a temperature dependent CPT-Violating (CPTV) axial time-like background (induced by the Kalb-Ramond tensor field of string theory) we discuss leptogenesis solving Boltzmann equation.The current work non-trivially modifies framework previous phenomenological approach authors where CPTV was considered to be constant (with no microscopic justification). The approximation though is shown capture main features leptogenesis. On comparing our analysis related chiral magnetic effect for...
We consider the renormalisation properties of non-Hermitian Yukawa theories involving a pseudoscalar (axion) field at or near $4$ dimensions. The non-Hermiticity is \cPT-symmetric where $\mathcal P$ linear idempotent operator (such as parity) and T$ an anti-linear time-reversal). coupling constants quartic scalar terms reflect this non-Hermiticity. path integral representing theory used to discuss Feynman rules associated with theory. fixed point structure group has \cPT- symmetric Hermitian...
For quantum mechanical anharmonic oscillator-type Hamiltonians, it is shown that there a relation between the energy eigenvalues of parity symmetric and <a:math xmlns:a="http://www.w3.org/1998/Math/MathML" display="inline"><a:mrow><a:mi mathvariant="script">PT</a:mi></a:mrow></a:math>-symmetric phases for weak coupling. The possibility such was conjectured by Ai, Bender, Sarkar on examining imaginary part ground state using path integrals. In coupling limit, we show conjecture true also real...
We discuss two classes of semi-microscopic theoretical models stochastic space-time foam in quantum gravity and the associated effects on entangled states neutral mesons, signalling an intrinsic breakdown CPT invariance. One class deals with a specific model foam, initially constructed context non-critical (Liouville) string theory, but viewed here more general effective quantum-gravity models. The relevant Hamiltonian perturbation, describing interaction meson medium, consists off-diagonal...
A classical solution for electromagnetic monopoles induced by gravitational (global) in the presence of a (four-dimensional) Kalb-Ramond axion field is found. The magnetic charge such nonzero strength, prevalent string theory. Bounds from current run LHC experiments are used to constrain parameters model. Because production mechanism depends on details model and its ultraviolet completion, bounds, presently, only indicative.