IFPU hosts and promotes a multi-disciplinary research program dedicated to investigating the fundamental laws of Nature as emerging from Cosmological and Astrophysical observations. The focus is on theoretical and phenomenological studies, with connection to the experimental and observational programs in the field and with attention paid to the scientific and technological transfer. Research themes developed by the institute are mainly connected to the areas listed below.
The aim is to explore particle physics through astrophysical phenomena and cosmology in regimes not accessible to the technology of particle colliders; at the same time, particle messengers can be exploited to study astrophysics and cosmology in regimes not accessible to traditional astronomical probes. Sample topics in this area include, e.g.: the investigation of particle dark matter candidates, the study of neutrino properties and neutrino astrophysics, as well as the open questions regarding cosmic rays.
Astrophysical Probes of Fundamental Interactions
The Universe is a natural lab for testing environmental conditions and energy regimes that can be well beyond the reach of terrestrial experiments, allowing one to probe or challenge extreme hypotheses. Topics of research in this area are rather diverse, spanning, e.g., from tests of violations of Lorentz invariance, to tests of variation of fundamental constants, up to studies of the equation of state for dense matter in neutron stars.
An extremely hot and dense Universe is predicted when extrapolating its current expansion back in time; relics from this early stage, such as the cosmic microwave background radiation and the primordial light elements, provide key evidence for the Standard Model of Cosmology. At the same time, several ingredients to model and understand the early Universe are missing in the Standard Model of Particle Physics. Open questions in this area include, e.g., what has driven inflation and how the Universe reheated after it, what mechanism generated the baryon asymmetry, whether sizeable primordial non-Gaussianity in density perturbations or a stochastic gravitational wave background exist and can shed light on particle physics close to the Planck scale.
Gravitational Wave Astrophysics
The recent detection of gravitational waves by the LIGO/Virgo collaborations has opened a new frontier for investigating the fundamental laws of Nature. Gravitational wave astronomy will allow for crucial tests of General Relativity, as well as of modified theories of gravity and quantum gravity effects. Compared to electromagnetic probes, it provides a complementary, and in some respect more powerful, diagnostic of compact objects. It may carry an imprint of physics beyond the Standard Model of Particle Physics, e.g., potentially revealing the existence of new ultra-light fields or the occurrence of first-order phase transitions in the early Universe. It is a new window for cosmology and cosmography.
Structures in the Universe:
The shaping of cosmic structures carries the imprint of the elementary constituents of the Universe, and of the physics laws that determine its evolution and its infant stages. Some of the open questions that are being investigated, include, e.g.: whether effects of dynamical Dark Energy and of modifications of gravity, that can hardly be distinguished from expansion tests, can be discriminated by the growth of cosmic structures; whether there are signs of primordial non-Gaussianity in the seeds of structure formation; whether cosmic structures at different scales may shed light on properties of dark matter particles, corresponding to, e.g., a self-interaction scale or free-streaming scale.
Theory & Phenomenology of Gravity
General relativity is among the most successful modern physical theories. On the other hand, in the last decades a number of theoretical problems as well as observational facts have led to a renewed interest in the phenomenology of classical extensions of Einstein’s theory as well as in quantum gravity models. Topics of research in this area include studying, e.g.: alternative theories of gravity; theoretical approaches to quantum gravity and their phenomenological implications; black holes and compact objects physics within and beyond general relativity; analogue models of gravity.