Polarity particles

This theme focuses on the generation of lateral optical forces on polarizable particles due to interaction with circularly polarized light and spin-orbit coupling effects near surfaces. Understanding these forces is crucial for manipulating nanoparticles, controlling nanophotonic elements, and enabling novel sorting and arrangement techniques beyond what is possible with conventional radiation pressure or gradient forces.

This research area investigates the mathematical and physical modeling of polarization phenomena in materials composed of polarizable, anisotropic particles, often within micropolar continuum theories and electrostatic frameworks. These models elucidate how particle shape, orientation, and dipole interactions influence macroscopic polarization properties, dust acoustic solitons, and electrostatic forces. These insights are fundamental to understanding and designing advanced materials, colloids, and dusty plasmas with tailored anisotropic and polarization-dependent behaviors.

This theme covers the role of polarization measurements and modeling in diverse contexts: characterizing comet dust particles from polarization patterns, describing three-dimensional polarization states in light fields, elucidating polarization fluctuations linked to particle shapes, and exploring active polar matter with orientational order and topological defects. These investigations combine experimental, theoretical, and numerical methods to connect observed polarization phenomena to underlying particle microstructure and dynamics, expanding knowledge in astrophysics, soft condensed matter, and biological active systems.

This theme addresses experimental and theoretical investigations into the polarity acquired by dielectric rods and agglomerate particles upon contact charging or triboelectric processes with various materials. It elucidates how material combinations, particle morphology, and density affect charge transfer outcomes and resulting polarization states. Such knowledge is key for applications in electrostatics education, industrial handling of powders, and understanding charge dynamics on small particles.

This line of research examines the synchronic usage patterns, pragmatic functions, and diachronic developments of response particles signaling affirmation or negation across languages, with a focus on Romance languages French and Italian. It challenges purely syntactic or semantic explanations and posits that understanding such particles requires incorporating historical pragmatics. The research also addresses sociolinguistic factors influencing particle frequency, polarity contrasts in replies, and the fluidity of functional paradigms in language change.

This theme explores the collective behavior, phase transitions, and defect dynamics in active polar matter. It covers how nematic or polar alignment interactions combined with excluded volume effects produce phase separation, re-entrant transitions, and clustering. It also investigates how disorder in interaction strengths affects long-range order and growth kinetics. Additionally, it focuses on the spontaneous flow patterns and annihilation dynamics of topological defects with implications for nonequilibrium statistical mechanics and biological systems.