For strongly correlated quantum systems, fundamental questions about the formation and stability of Floquet-Bloch sidebands (FBs) upon periodic driving remain unresolved. Here, we investigate the impact of electron-electron interactions and perturbations in the coherence of the driving on the lifetime of FBs by directly computing time-dependent single-particle spectral functions using exact diagonalization (ED) and matrix product states (MPS). We study interacting metallic and correlated insulating phases in a chain of correlated spinless fermions. At high-frequency driving, we obtain clearly separated, long-lived FBs of the full many-body excitation continuum. However, if there is significant overlap of the features, which is more probable in the low-frequency regime, the interactions lead to strong heating, which results in a significant loss of quantum coherence and of the FBs. Similar suppression of FBs is obtained in the presence of noise. The emerging picture is further elucidated by the behavior of real-space single-particle propagators, of the energy gain, and of the momentum distribution function, which is related to a quantum Fisher information that is directly accessible by spectroscopic measurements.

Active environments challenge the conventional description of thermal reservoirs because their intrinsically nonequilibrium dynamics. I will discuss how microscopically modeled active baths, and how the nonequilibrium features becomes visible in the stationary fluctuations of immersed probes. Activity modifies relaxation, breaks fluctuation–response relations and energy equipartition, and can generate non-monotonic transport, negative differential conductivity and current reversal in otherwise linear systems. I will also show how similar anomalies can arise from the kinetics of the system–reservoir contact itself, highlighting a broader principle: reservoirs are dynamical components of a system, and their microscopic properties can qualitatively control fluctuations and transport.

The remarkable agreement between the observed light-element abundances and the predictions of big bang nucleosynthesis (BBN) makes BBN a powerful probe of physics beyond the Standard Model (BSM). In this talk, I will present the BBN constraints on a specific BSM particle, the Majoron, and discuss its cosmological implications. I will also highlight the caveats of the standard BBN scenario in light of the long-standing cosmological lithium problem and briefly outline a possible solution.

Galaxies are the visible building blocks of the Universe where everything happens, from stars to planets to life itself. Interestingly, while some galaxies appear beautiful and orderly, others appear completely distorted, twisted, and chaotic. These irregular galaxies arise due to galaxy collisions -- one of the most spectacular events in the Universe. In this talk, we will explore galaxy collisions, and understand: how do they occur? why do they occur? Do galaxy collisions lead to complete destruction of galaxies or creation of something new? and, How our own Milky Way is currently undergoing a collision with another galaxy intruder? In essence, galaxy collisions and mergers are among the most important drivers of galaxy evolution across the cosmos.

Quantum statistics is traditionally viewed as a kinematic property that determines how particles occupy available states. In this talk, I will show that quantum statistics can itself serve as a powerful resource for energy conversion in a transport setting. Focusing on particles obeying Haldane exclusion statistics, we demonstrate that statistical interactions generate an intrinsic breaking of particle-hole symmetry, even in the absence of interactions, band asymmetry, or external symmetry-breaking mechanisms. The consequences for transport are profound. The symmetry breaking produces strong thermoelectric response and large deviations from the Wiedemann-Franz law. In particular, exclusion statistics can substantially enhance the thermoelectric figure of merit, establishing a new route toward efficient energy harvesting driven purely by quantum statistics. Building on this insight, I will show that exclusion statistics can be elevated to the status of a genuine thermodynamic resource. Within a nonlinear Landauer framework, quantum heat engines employing fractional-statistics carriers can surpass performance bounds previously regarded as universal for fermionic systems. Bosonic and fractional-statistics working media exhibit enhanced power output, improved efficiency-power trade-offs, and superior refrigeration capabilities. Finally, I will discuss a realistic realization based on thermally driven magnon transport, where the predicted advantages emerge in an experimentally accessible spin-caloritronic setting. These results suggest a new paradigm for quantum thermodynamics in which statistical correlation and not interactions, topology, or coherence alone become the fundamental resource governing transport, refrigeration, and energy conversion.

The Non-Hermitian Skin Effect (NHSE) represents a foundational shift in non-Hermitian wave physics, traditionally characterized by robust, single-edge localization driven by non-reciprocal coupling mechanisms or active bulk gain and loss. This talk explores the conceptual evolution from this established conventional paradigm toward a novel 'mesoscopic' regime, where non-Hermiticity emerges exclusively through radiative boundary leakage within an otherwise lossless photonic crystal structure. In this mesoscopic landscape, the system deviates from conventional singular edge-pinning, instead demonstrating symmetric, dual-edge localization governed by distinct size-dependent properties linked to the total system dimension. To characterize this behavior, Von Neumann entanglement entropy is utilized as a diagnostic tool, providing a quantitative measure of boundary interactions. The observed logarithmic growth patterns in this entropy offer rigorous verification of long-range, non-local correlations connecting the physical boundaries, effectively capturing the transition from isolated modes to an interconnected boundary state. In addition to this theoretical framework, the talk will outline experimental plans to map the phase transition from the mesoscopic regime to the conventional NHSE, utilizing high-precision microwave photonic crystal architectures and controlled bulk loss modulation. By establishing a unified physical framework for boundary-engineered wave trapping, this research outlines a passive, highly tunable pathway for next-generation technological integration, particularly in the fields of on-chip AI acceleration, quantum information processing, and advanced non-reciprocal photonic circuitry.

We have been using swift heavy ion beams, lasers and gamma radiations to synthesize and modify nanostructures of elemental as well as compound semiconductors and subsequently characterizing them using XRD, Raman and TEM. The dependence of the resulting new class of nano-materials on energy and fluence of the initial swift heavy ions, is being investigated in detail. These external probe radiations modify the electronic and optical properties of nano-structures (quantum wells, quantum dots and nanowires). Some applications of these studies in Nano-Science and Nanotechnology will be presented.