The Muon g-2 experiment at Fermilab (E989) is currently measuring the muon magnetic anomaly with a goal precision of 140 parts per billion, which will be a fourfold precision improvement over the current best measurement by the previous muon g-2 experiment at the Brookhaven Laboratory (BNL). The BNL-measured value of the muon magnetic anomaly and the corresponding Standard Model (SM) best estimate, differ by more than three standard deviation which inspired the current measurement as well as a theoretical drive for a significantly more precise calculation of the muon magnetic anomaly to rule out (or establish) statistical fluctuation as the origin of such a huge discrepancy. Stable central values along with 4-fold precision improvements in both theoretical (SM) and experimental fronts, would imply a ~ 7σ discrepancy and that will be a clear hint of the physics beyond the Standard Model. Such unprecedented precision demands state-of-the-art technological improvements in all involved components to keep the systematic uncertainty below 70 ppb. This paper reports the current status of the E989 experiment after two years of data acquisition.

Among various types of two-Higgs-doublet models, the type-X model is known to accommodate the muon g-2 anomaly. We will discuss various features of the model in relation to muon g-2 and the prospect of testing them in future collider experiments.

Due to the exponential growth of the dimensions of the Hilbert space with the number of particles, quantum many-body problems continue to be one of the greatest challenges in physics. In this talk, I will give an introduction to Tensor network techniques which can be used to study challenging quantum many-body problems. In particular, I will talk about some of our recent works in the group where we employ these techniques to study an actual quantum magnet Ca10Cr7O28, recently discovered to have properties of a quantum spin liquid. I will then talk about an annealing algorithm based on tensor networks for 2D finite temperature states. I will also show how they can be used as a benchmarking and guiding tool for experiments involving cold atoms.

References:
1. A Kshetrimayum, C Balz, B Lake, J Eisert arXiv:1904.00028 (2019)
2. A Kshetrimayum, M Rizzi, J Eisert, R Orús PRL 122 (7), 070502 (2019)
3. A Kshetrimayum, H Weimer, R Orús Nature communications 8 (1), 1291 (2017)

In this talk, I will discuss the searches for Axion-Like-Particles (ALP) at future e+ e- colliders. In particular, I will discuss the collider phenomenology of ALP-photon-photon and ALP-photon-dark photon couplings in the context of the future e+ e- colliders. I will illustrate that these interactions can be efficiently probed at future e+ e- colliders in the di-photon+missing energy channel, where the missing energy has the origin in the invisible dark photon in the final state. The di-photon+missing energy channel turns out to be more sensitive probe of the ALP than the traditional tri-photon channel.

Schrodinger queried 50 years back what will happen if photon had a small mass. He answered that Electrodynamics both classical and quantum will acquire only small corrections. He used this to establish a bound on the mass of photon which is valid even now, except for some improvements in experimental accuracies. We revisit this question from new perspective of asymptotic symmetries, cosmology and dark matter. It rekindles old questions on the nature of vacuum and aether!! Be prepared for surprises!!

Murray Gell-Mann who recently passed away was a tremendously influential physicist best known for his contributions to elementary particle physics, especially to quantum field theory, and the strong interactions. His repertoire was far larger. In this talk we will recall some of the features of his extraordinary life and work and say a few words about his ideas beyond elementary particle physics.

In the year 1924, in a couple of papers from Dhaka University, S.N. Bose gave a radically new derivation of the black body radiation law. Abraham Pais, in his scientific biography of Albert Eisntein, remarked that this work is the last of the four fundamental papers in old quantum theory, the other three being by Planck, Einstein and Bohr. Bose introduced the concept of indistinguishability in physics which was the big idea that shaped the subsequent development of quantum mechanics, eventually leading to quantum field theory. We give a pedagogical presentation of this development, primarily aimed at the students.

The field of laser-produced plasmas (LPP) has greatly attracted the research community because of its wide range of applications, which include pulsed laser deposition, generation of X-rays and ion beams, plasma based acceleration etc. This talk will open with a general introduction to plasmas (ultrafast LPPs in particular), followed by a discussion of the general plasma diagnostic methods (optical and electrical). Experimental determination of plasma density and temperature will be discussed, and the spectral and temporal characterization of LPPs generated in metallic targets will be elaborated. X-ray emission from LPPs of noble metal nanoparticle suspensions will be discussed. Some applications including High Harmonic Generation (HHG) will be outlined.

The present era is characterized by the dominance of mobile communications and the range of applications that provides. They work in the microwave frequency range and hence why microwaves are being used for such applications will be reviewed. As the demand for mobile communication increases, demand for new devices also increases. Not only it places new demands on design, but also new materials and phenomena are being pressed into service. For example, materials with high dielectric constant, low dielectric loss and temperature independent properties are used for making microwave dielectric resonators (DRs) while using electromechanical resonances exhibited by ferroelectric thin films, miniature resonators like film bulk acoustic resonators (FBAR) and related high overtone resonators (HBARs) are being developed for 5G applications. High Q resonators are useful both in communication as well as in sensors. In addition, efforts are being made to achieve these devices on flexible, polymer and biocompatible substrates. Ferroelectric materials exhibit a voltage dependent dielectric constant and that can be used for realizing varactors using thin films in a relatively simple technology. Using such varactors, it is possible to develop filters, phase shifters and tunable impedance matching networks which are voltage tunable. At smaller voltages, they can be tuned using less than 5 volts and hence can be tuned using digital circuits paving the way for a means for realizing software defined radios. These films are being made for such applications using RF sputtering and Pulsed Laser Deposition. In this talk, these topics and related activities that are being pursued at University of Hyderabad will be presented.

Thermal dark matter scenarios based on light (sub-GeV) fermions typically require the presence of an extra dark sector containing both a massive dark photon along with a dark Higgs boson. The latter typically generates both the dark photon mass and an additional mass term for the dark sector fermions. We study the phenomenology and experimental constraints on two minimal, self-consistent dark sectors that include such a light dark Higgs boson. In one the dark matter is a pseudo-Dirac fermion, in the other a complex scalar. We find that the constraints from BBN and CMB are considerably relaxed in the framework of such minimal dark sectors. We present detection prospects for the dark Higgs boson in existing and projected proton beam-dump experiments. We emphasize in particular the effect of the dark Higgs boson on both detection prospects and cosmological bounds. We point out that in addition to the well studied pseudo-Dirac regime, this model can achieve the correct relic density in three different scenarios, and examine in details their properties and experimental prospects. We show that future searches at experiments like Xenon1T or LDMX can probe all the relevant parameter space, complementing the various upcoming indirect constraints from astrophysical observations.

In this talk I will discuss two things; one is about two-dimensional disk structures and second, self- similar solutions for the finite size of the disk around the black hole. We have solved steady-state, axisymmetric viscous 2D fluid equations of motion for accretion and outflows in spherical polar coordinates (r, θ, φ). First time in the analytical study, we have used two azimuthal components of the viscous stress tensors namely, τ_{rφ} and τ_{θφ}. We found supersonic and subsonic regions in the inflow region and the outflows occurred in the subsonic inflow region above the equatorial plane. We also found that the structure and size of the 2D disk are affected by the viscosity and the ADAF size of the disk. We also explored the outflows, no outflows, and failed outflows solutions around the BH. Second part I will talk about the hybrid disk geometry and implications of hybrid disk and self-similar solutions.

Symmetry-based studies have been very successful to explain the observed mixing pattern of neutrinos. Among number of such approaches, \mu-\tau reflection symmetry, which predicts θ_{23}=Π/4, δ=\pm Π/2 together with non-zero θ_{13}, attracts a lot of attention in recent times. On the other hand, the type-I seesaw mechanism remains the simplest and elegant one to describe the theory behind the neutrino mass. In this talk, we shall discuss the μ - τ reflection symmetry which we embed into the minimal seesaw model to explain both the neutrino mass and mixings. Furthermore, to explain the latest global best-fit values of neutrino oscillation data, which favor non-maximal values of θ_{23} and δ, we shall talk about the breaking of such symmetry. We shall also talk about the generalize CP-symmetry and bi-large ansatze to explain the leptonic mixing patterns. Finally, we shall discuss the consequences of such symmetry for the long baseline neutrino oscillation experiment, DUNE as well as neutrinoless double beta decay experiments.

There will be two sections in the talk that will consist of the study of optical conductivity and thermoelectricity based on semi-Dirac materials.

In the first section, we show that the gap parameter in semi-Dirac material induces a large degree of sensitivity for interband optical conductivity with respect to the polarization direction. The optical conductivity reveals an abruptly large value at a certain frequency for light along a particular polarization direction while it is significantly suppressed along the direction orthogonal to the former. The direction-dependent optical conductivity may, in turn, be used to uniquely predict the dispersive nature of the two-dimensional semi-Dirac materials, in addition to other possible applications in the field of transparent conductors.

In the second section of the talk, we give a prediction that the gap parameter manifests itself by enhancing the thermoelectric figure of merit $zT$ as the chemical potential crosses the gap, followed by a sign change in the Seebeck coefficient around the same point. Subsequently, whenever the chemical potential crosses the gap potential parameter, there is a well-balanced maximum of the power factor and the efficiency of the thermoelectrics. An optimal operating point where co-maximization of the power efficiency occurs is consequently singled out for the best thermoelectric performance. This section of our work will pave the way for the use of two-dimensional semi-Dirac materials for thermoelectric applications.

References:
1. A. Mawrie and B. Muralidharan, Physical Review B 100, 081403(R) (2019).
2. A. Mawrie and B. Muralidharan, Physical Review B 99, 075415 (2019).

We present a dynamical toy model for an expanding universe inside a black hole. The purpose of the model is to suggest a possible reconciliation between the observation that black holes are well described by the classical solutions and the fact that the theoretical resolution of space-time singularities leads to a bounce for the collapsing matter.

The Raychaudhuri equations and its consequences will first be introduced using simple examples from mechanics and other areas of physics. Thereafter, we move on to a quick derivation of the equations for the kinematic variables (expansion, shear, rotation) describing the evolution of geodesic congruences in Riemannian and pseudo-Riemannian geometries. Subsequently, the focusing theorem will be presented and its role in the context of the singularity theorems highlighted briefly. We end with a summary of the applications of the Raychaudhuri equations in diverse contexts (including some recent results), thereby emphasizing its ubiquitous nature.

The structure of hadrons is an important problem that has far-reaching consequences. The lepton-proton scattering experiments are aimed at studying the structure of the protons. But, the experiments are less accurate in the low energy regime because of the difficulties involving the soft bremsstrahlung photons. This leads to a poor understanding of the low energy structure of hadrons. Heavy Baryon Chiral Perturbation Theory (HBChPT) is a systematic expansion of the chirally invariant Lagrangian in the low-energy regime with baryons as fundamental degrees of freedom. Thus, HBChPT forms a convenient tool to study the lepton-proton scattering process. In this talk, I will discuss our recent efforts to study low energy lepton-proton scattering using HBChPT.

We theoretically propose and experimentally realize a phonon laser using an optically levitated nanoparticle. In our system, mechanical gain and nonlinearity are supplied optically. We present theoretical evidence for stimulated emission of phonons, and experimental observations of i) threshold behavior as a function of gain, ii) the transition in phonon statistics from Boltzmann to Poisson across the threshold, and iii) subthermal phonon number squeezing far above threshold. The experimental data agrees well with our microscopic quantum mechanical theory. Our work represents a substantial advance in the generation of coherent phonons in levitated systems and can be readily extended to other physical platforms.

It is an integral fact that QCD is an integral part of the Standard Model as well as any of its extensions. But in the low energy sector it is highly non-perturbative. The only rigorous method to treat such a theory is the lattice. In this talk, after a very brief introduction of this method, several applications specifically designed to search for new physics will be discussed.

Resonating Group Method (RGM) is a technique used to study many-body systems. Since its formulation in 1937, such a methodology has been state-of-the-art in studies relating to clustering phenomena in the light nuclei. It has also been extensively used in studying condensed matter systems. In this talk, I plan to discuss the formal aspects of RGM and its applications to nuclear physics.

C-MET a scientific R&D laboratory under Ministry of Electronics & IT is working on requirement driven R&D in the fields of Microwave substrates, sensors and actuators, Supercapacitors, purification of metals, wide bandgap compound semiconductors, recycling of electronic waste in environmental friendly manner, extraction of refractory metal like hafnium at pilot plant scale, antennas for NavIC, Li-ion batteries and LTCC packaging. Broadly the areas of R&D status are covered.

Microwave dielectric materials gained immense importance in wireless applications and many of the high dielectric ceramics are composed of rare earth elements as one of the constituents which in turn help in fine tuning the end properties by judiciously substituting rare earth ions having varying ionic radii. The personal communication devices and other wireless technology industries, such as direct broadcasting, global positioning systems, mobile communication systems etc. have witnessed an explosive and unprecedented growth in applications. The application areas are fast ranging from simple dielectric resonator to complex 3D modules realized through Low Temperature Co-fired Technology. More recently, rare earths based Ultra Low Temperature Co-fired Ceramics (ULTCC) are also finding applications in realizing miniaturised and cost effective devices including Substrate Integrated Waveguide (SIW) circuits. In order to meet these stringent requirements, novel materials with high dielectric constant and low loss tangent are required. High dielectric constant reduces the circuit size since the wavelength travelling through the medium is inversely proportional to the square root of the dielectric constant. On the other hand, extremely low loss tangent improves the signal integrity and avoids cross talks. Cu-cladded rare earth ceramic filled PTFE planar laminates are the ideal choice for high end microwave circuit fabrication which are currently available only from imported sources. Understanding the need for indigenous technology, C-MET has developed a proprietary and patented process methodology comprising of Sigma Mixing, Extrusion, Calendering followed by Hot pressing (SMECH Process) to fabricate dimensionally stable planar and isotropic PTFE/ceramic composite laminates. Pore free and dimensionally stable planar laminates have been prepared by incorporating variety of rare earth titanate ceramics in the PTFE matrix through SMECH process. C-MET has successfully developed wide variety of filled PTFE substrates with dielectric constant ranging from 2.2 to 14.8 together with ultra-low loss tangent ( 0.0018 at 10 GHz) and the technology for the same is already transferred to Industry for commercial production. High power solid state amplifiers have been fabricated by Raja Ramanna Centre for Advanced Technology (RRCAT), Department of Atomic Energy, Indore operating at a centre frequency of 505.8 MHz, which can withstand output power up to 750 kW. Excellent RF performance was obtained in terms of output power, gain and efficiency during system level evaluation and accordingly the high power solid state amplifiers have been successfully deployed in INDUS-2 particle accelerator.

Superconducting Quantum Circuit elements, the Josephson junctions, in particular, play a pivotal role in the diverse field, like, nano-scale magnetometry and quantum computation using superconducting circuits. In this talk, I shall describe the nano-fabrication and measurements of different types of superconducting quantum circuit elements, particularly, the different avatar of Josephson junctions and superconducting resonators. The detailed nano-fabrication processes, which involved electron beam and photolithography, reactive ion etching, thin film evaporation, to mention only a few, will be spelled out. In this regard, I shall describe a thermal model to explain the origin of hysteresis in nano-bridge quasi-Josephson element and explain how the model, followed by experimental findings, would help us unearthing new phenomena and optimizing device design. I shall, then, present our experimental results on high-impedance kinetic-inductance resonators, quantum-noise-limited microwave amplifier, and microwave single-photon-detector. Finally, I shall touch upon our recent unpublished result on nano-bolometer with record-breaking low noise equivalent power.

In this talk, we will talk about our theoretical study on the quantum correlations present in an optomechanical system. Under experimentally achievable conditions, we will demonstrate that a significant enhancement of the steady-state entanglement could be achieved at a considerably lower driving power, which is also extremely robust with respect to the system parameters and environmental temperature. We then employ Gaussian quantum discord (QD) as a more genuine measure of the quantumness of the correlation.
[This work is published in JOSA B, Vol. 34,1503 (2017) and recognised as one of the top downloaded papers of 2018 in the journal.]

The technique/concept that led to first half of the Nobel Prize.

The technique/concept that led to second half of the Nobel Prize.

We present a framework that allows to evaluate the next-to-leading order (NLO) corrections in QCD of the Di-photon production through gluon fusion, retaining full top quark mass effects, numerically. Our method starts from the generation of the necessary amplitudes followed by the reduction of the integrals using the Integration-By-Parts reduction and the numerical evaluation of the master integrals via combination of differential equation and sector decomposition. Specifically, we will show the results for the inclusive cross-section and the invariant mass distribution for the first time, thereby exhibiting the importance of the inclusion of the top mass effects.

Despite more than half a century of research, the fundamental nature of the glass transition remains one of the major open questions in materials science and condensed matter physics. Computer simulations have provided key insights into this problem, but their ability to firmly establish the underlying nature of glass formation have been limited by the extreme computational difficulty of directly probing the deeply supercooled regime most relevant to this process. Here we describe a new protocol for simulation of the glass transition enabling facile access to in-equilibrium segmental relaxation times approaching and exceeding one microsecond - well into the deeply supercooled regime of most glass-forming liquids. Coupled with a well-validated strategy for extrapolation to experimental timescales, this approach provides vastly improved prediction of experimental glass transition temperatures. Here, we combine data acquired through this protocol for the deeply supercooled regime of polymeric, inorganic, organic, and metallic glass formers to identify microscopic phenomenological features shared across all classes of glass-forming liquid in the deeply supercooled regime. Further, correlations between glass formation and conductivity of polymeric materials are addressed.