Neutrino astrophysics
Neutrino astrophysics has brought milestones in our understanding of neutrino properties and of stellar evolution. Neutrinos are still tightly linked to key open questions in astrophysics, including unravelling the mechanisms of the death of massive stars and the site(s) where the heavy elements are made. Flavor oscillations in vacuum and in the Sun are well understood phenomena. However, neutrino flavor evolution in dense environments, such as core-collapse supernovae and accretion disks around binary neutron star mergers or black holes, is revealing many surprises. In particular neutrino self-interactions render the study of flavor evolution in media a complex many-body problem. In this talk I will highlight major advances in the field, the importance of future observations and its formal connection to condensed matter and to atomic nuclei.
Friday, 31 March 2017, ore 14:30 — Aula Magna
Fundamental cosmology with multi-wavelength synergies
'Synergy' means 'the interaction of two or more agents to obtain a combined effect greater than the sum of their separate effects'. With this in mind, in this talk I shall present my current lines of research, all relying on developing novel combinations of astrophysical and cosmological observables to the aim of testing the foundations of the concordance cosmological model. Specifically, I shall discuss cosmological tests of gravity and inflation on the largest cosmic scales, indirect detection of particle dark matter signatures, and studies of dark energy and modified gravity models.
Friday, 24 March 2017, ore 14:30 — Sala Wataghin
Inflation after the Higgs
The inflationary paradigm is able to explain why our universe is so homogeneous and isotropic and, at the same time, why it contains inhomogeneities, such as galaxies and clusters of galaxies. We will review the current status of the inflationary cosmology, pointing out possible connections to the physics of the Standard Model Higgs.
Friday, 17 March 2017, ore 14:30 — Sala Wataghin
The Belle-II physics program
Friday, 10 March 2017, ore 14:30 — Sala Wataghin
Long-term climate variability: what we can learn from terrestrial and extraterrestrial archives
Climate variations happen on all time scales. Among them, the centennial scale is particularly interesting, being comparable to the scale of human life and to the modern variation related to anthropogenic forcing. Instrumental observations, covering only a couple of centuries, are influenced by human activity and are too short to study natural centennial and multicentennial variability. The interest towards the past is also related to the challenging problem of predicting climate variability. The key to gaining information on long timescales is the measurement of proxy records in different archives, e.g. tree rings, corals, cave deposits, ice and ocean sediment cores. At present, paleoclimatic research needs long and high-resolution time series describing past climate variations and allowing to relate the observed variability with both internal and external forcings, such as solar activity and volcanic eruptions. I will illustrate some modern approaches to the study of archives, highlighting their advantages and limitations. The paleoclimatic research lines carried on at our Department will then be presented, with focus on recent results.
Friday, 24 February 2017, ore 14:30 — Sala Wataghin
Gravitational Waves and Coalescing Black Holes
Two of the most novel predictions of Einstein's theory of General Relativity were discovered soon after its creation one century ago:
Black Holes (Schwarzschild, January 1916) and Gravitational Waves (Einstein, June 1916). It took more than 50 years to grasp the physical significance of these theoretical discoveries. The recent discovery of several gravitational wave events by the two Laser Interferometer Gravitational-Wave Observatory (LIGO) interferometers has brought the first direct evidence for the existence of black holes, and has also been the first observation of gravitational waves in the wave-zone. The talk will review the theoretical developments on the motion and gravitational radiation of binary black holes that have been crucial in interpreting the LIGO events as being emitted by the coalescence of two black holes. In particular, we shall present the Effective One-Body formalism which has been crucial in allowing one to compute the bank of 250 000 templates that has been used to search coalescence signals, and to measure the masses and spins of the coalescing black holes.
Thursday, 16 February 2017, ore 14:30 — Aula A
The worls of electromagnetic matter
We will discuss the properties which make the dynamics of a plasma different from the one of matter at thermodynamical equilibrium, examining apparently different problems in astrophysics, nuclear fusion and relativistic plasmas, sharing the common feature of being dominated by a collective non-linear interaction. At the end, we will discuss future developments in the field of plasmas produced by ultra-intense laser-pulses and dominated by QED processes.
Friday, 3 February 2017, ore 14:30 — Sala Wataghin
Axions and lattice-QCD
The axion is a hypothetical elementary particle, which is supposed to solve two major puzzles in fundamental physics. First they can explain, why the strong interaction (QCD) is surpisingly symmetric under exchanging left and right. Secondly axions also offer a solution to another long-standing puzzle: they are a natural candidate for particles out of which the mysterious Dark Matter is made of. In this talk I describe how theory, and in particular lattice QCD calculations on supercomputers, can help the experimental search for these particles.
Friday, 27 January 2017, ore 14:30 — Sala Wataghin
Heavy ions in therapy and space
Heavy ion biophysics is an emerging research field with two main applications: cancer radiotherapy and space radiation protection. Both fields are rapidly growing. Particle therapy is generally acknowledged as a cutting edge methodology, and solid plans for the first heavy ion therapy center are established in USA within the cancer moonshot program. On the other hand, the commitments of the space agencies toward exploration make urgent to tackle the problem of radiation exposure, a potential showstopper for manned colonization of the Solar system.
Both particle therapy and space radiation fields share many common topics, and we will give three examples: light flashes, radiation-induced carcinogenesis, and hibernation. We will argue that ground-based accelerator research is essential for solving both problems.
Friday, 20 January 2017, ore 14:30 — Aula Magna
The epigenome - a new code superimposed on the DNA
Since the sequencing of the human genome, scientists embarked on a long trip trying to decipher how a long DNA sequence based on only four letters - the genome - could originate the complexity of life. On one hand, all the cells in a human body share the same genome, while they originate remarkably different organs and tissues. On the other hand, it became clear that the environment where we live in, the food we eat, they all deeply influence our cells. Eventually, it all depends on which subset of the genome is used, and how its activity is modulated. The fine tuning of this process is controlled by a new code, the epi-genome. This is superimposed on the genome, and critically contributes defining which genes are needed in space (in the various organs), in time (during aging), and in a specific environmental setting (during stress or starvation) in our body. This seminar will illustrate our current understanding on this emerging layer of complexity, including how we can read and possibly modify the epigenetic code.
Friday, 2 December 2016, ore 14:30 — Aula F