Understanding how ultrahigh energy cosmic rays (UHECRs) reach energies in excess of 1e20 eV stretches particle acceleration physics to its very limits. In this talk, I will discuss how such energies can be reached, using general arguments that can often be derived on the back of an envelope. I will review possible particle acceleration mechanisms, with special attention paid to shock...
Multi-messenger astrophysics has emerged as a rapidly growing field of research in the last decade, providing unique new insights into the properties of high-energy astrophysical sources. Such insights have been made possible by the complementary information carried by photons, cosmic rays, neutrinos, and gravitational waves about the astrophysical environments and processes in which they are...
We live in a golden age for astro-particle physics, with a significant number of experiments actively monitoring high-energy Universe. Many of these probes provide excellent tests of particle physics models of dark matter particles. In particular, experiments such as Fermi -LAT, AMS-02, Ice Cube, ... are significantly cutting into the parameter space of one of the most popular candidates, the...
Direct measurements of cosmic rays have finally entered a precision era. Large particle physics experiments operating in space allowed high-statistic measurements of the cosmic ray energy spectra, of their chemical and isotopic composition, and of the rare anti-matter components, in a wide energy range. In this talk, I will review the progress in the field, the recent results, their...
Gamma-ray astronomy studies the most powerful phenomena in the Universe and tests the limits of our understanding of the laws of physics in extreme conditions. Decades of continuous improvements in experimental techniques for space-borne and ground-based observations have led to an ever-increasing sky and energy coverage. In this presentation I will discuss how the current generation of...
The field of extreme space weather has undergone substantial development during the past 20 years, beginning in 2003 with the uncovering of magnetic records from India for the 1859 Carrington storm. More recently, new windows on extreme solar-terrestrial events have opened with studies of cosmogenic nuclide events and historical aurorae and the discovery of superflares on solar-type stars. ...
The Sun drives a supersonic wind which inflates a giant plasma bubble in our very local interstellar neighborhood, the heliosphere. Its boundaries and the turbulent magnetic field shield the solar system from much of the interstellar medium as well as the low-energy portion of galactic cosmic rays (GCRs) which are accelerated primarily by super-nova-driven shocks in our galaxy. The heliosphere...
