Marco Baiesi, Fulvio Baldovin, Nicola Bartolo, Andrea Brignole (INFN), Luciano Canton (INFN), Davide Cassani (INFN), Gianguido Dall’agata, Francesco D’Eramo, Ferruccio Feruglio, Lorenzo Fortunato, Stefano Giusto, Marco Laveder, Kurt Lechner, Silvia M. Lenzi, Michele Liguori, Paolo Lotti (INFN), Enrico Maglione, Pieralberto Marchetti, Amos Maritan, Luca Martucci, Antonio Masiero, Pierpaolo Mastrolia, Sabino Matarrese, Marco Matone, Enzo Orlandini, Paride Paradisi, Massimo Passera (INFN), Stefano Rigolin, Flavio Seno, Dmitri Sorokin (INFN), Attilio Stella, Samir Suweis, Antonio Trovato, Andrea Vitturi, Roberto Volpato, Andrea Wulzer, Fabio Zwirner

Alexandra Carvalho, Jorge De Blas, Eugenio Del Nobile, Fotis Farakos, Purnendu Karmakar, Andrei Lazanu, Alessio Marrani, Praxitelis Ntokos, Tomohiro Oishi, Luca Vecchi

Sukruti Bansal, Giampaolo Benevento, Alessandro Bombini, Nicolò Cribiori, Andrea Galliani, Maria Chiara Guzzetti, Dionysios Karagiannis, Stefano Lanza, Filippo Oppizzi, Giorgio Orlando, Andrea Pattori, Federico Pobbe, Amedeo Primo, Andrea Ravenni

The activities of the Theoretical Physics group span a wide range of research directions, focused on Particle Physics and Astroparticles, Field and String theory, Nuclear Physics, Cosmology and Statistical Physics.

Particle Physics is the science which identifies nature's constituents and interactions at the most fundamental level, with an emphasis on comparing theoretical ideas with both terrestrial experiments and astrophysical observations. Particle physicists are currently involved in identifying how cosmological observations, terrestrial accelerator and underground experiments constrain the theoretical possibilities for physics beyond the Standard Model. Our group is pursuing diverse research lines within the framework of theoretical particle physics, ranging from astroparticle and cosmological physics that describes the physics of the early Universe, to the physics of the Standard Model and beyond that describes the fundamental interactions and matter of the subnuclear world. Research areas of the Standard Model include expertise in flavour physics (g-2, neutrino, K and B physics, CP violation) and Higgs physics. Group members have played a major role in exploring many different aspects of physics Beyond the Standard Model, such as effective field theories, supersymmetry, extended gauge group models, extra dimensions and string inspired phenomenology. A vivid research activity focuses on the structure of Quantum Field Theories emerging from the analytic properties of scattering amplitudes. By combining high-energy physics and mathematics, our group works on the development of novel methods in perturbative gauge theory, reaching from formal developments to phenomenological applications.

Our group is also very active in the area of Astroparticle Physics, which lies at the intersection between the microcosmos of fundamental particles and the astronomical macrocosmos of galaxies and clusters. Our goal is to shed some light on fundamental questions about dark matter, dark energy and neutrino physics by connecting particle physics and astrophysical and cosmological observations. Several members of our group are studying the possibility of producing dark matter directly at the Large Hadron Collider or seeing it through its decays into highly energetic particles that are produced by astrophysical sources and detected by earth-based experiments. Studying the properties of neutrinos and determining its masses and mixing angles in future oscillation experiments is also a priority of our group. We are not only interested in accelerator signatures, but also in the astrophysical sources such as supernovae or relic neutrinos. Finally, a detailed knowledge of the neutrino parameters might shed some light into the origins of the matter/anti-matter asymmetry which, at the moment, is best understood in terms of the Leptogenesis scenario.

While classical and quantum field theories offer today's standard description of classical gravity, of electromagnetism and of the nuclear forces, string theory is currently the most viable candidate for a unified theory of physics which describes all forces of nature at the quantum level. The research interests of our group cover several areas in Field and String Theory. A considerable part of our activity is focused on supersymmetric models. In particular, Super-Yang-Mills theories are investigated to better understand the properties of their moduli space and their non-perturbative behaviour, while Supergravity theories are used as tools to better understand the mechanisms of supersymmetry breaking and as effective theories for string theory. Supergravity and string theory are also used to better understand the physics of black holes and the information problem. Other research directions explored by our group include the gauge-gravity correspondence, string-motivated phenomenological models, geometric aspects of the brane dynamics, the measure on the supermoduli space relevant for string amplitudes, higher spin models, lower dimensional field theories, conformal field theories and Chern-Simons gauge models for high temperature superconductivity.

The research activity in Nuclear Theory has the unifying characteristic of correlating the phenomenology to fundamental microscopic approaches. A first research line concerns the influence of many-body correlations on the nuclear spectroscopic properties, with emphasis on both single particle and collective excitations. The properties of the effective interaction are studied in the shell model in nuclei far from stability, both in neutron-rich nuclei, where changes in the magic numbers are observed, and in proton-rich nuclei where the isospin symmetry breaking effects manifest. The structure of exotic nuclei is also explored by using group-theory based methods, solving the few-body problem (both with fermions and with preformed cluster structures) by using algebraic based techniques. A second line concerns the dynamics of nuclear excitations and the reaction mechanisms, in particular in reactions with weakly-bound nuclei and/or large neutron excess (e.g. the excitation of the low-lying dipole modes and of the role of the pairing interaction in two-particle transfer processes). We are also interested in studying the one- and two-proton spontaneous emission from excited states. Another line of research is based on a theoretical approach (called MCAS) that describes the nuclear scattering processes starting from an effective nuclear cluster-like Hamiltonian which accounts the soft (low-energy) correlations of the target/projectiles.

Our group has also a strong interest in research focusing on the interplay between Cosmology and Fundamental Physics, involving studies of the Early Universe and of the present day cosmic acceleration. We consider both theoretical and observational aspects.

Early Universe studies revolve around inflationary mechanisms for the generation of primordial cosmological perturbations, with special focus on the study of beyond Gaussian statistics of primordial fluctuations and of the Primordial Gravitational Wave (PGW) background. Regarding low-redshift cosmic acceleration, our interest is centered on the study of Modified Gravity (MG) models on cosmological scales.

Finally, several members of our group are active in areas ranging from Statistical Mechanics to Complex Systems Physics. We deal with interdisciplinary topics such as biopolymer and protein physics, liquid crystal dynamics, collective motions in self-propelling particle systems, physics of ecological systems, biological and physics econophysics. Our approach to these topics includes data mining, data analysis, statistical analysis, computational and analytic modeling.

For more information, news, and seminars, please visit the webpage of the INFN Theoretical Physics group in Padua.