Related papers: The Extreme Physics Explorer
Polarimetry remains a largely unexploited technique in observational X-ray astronomy which could provide insight in the study of the strong gravity and magnetic fields at the core of the Constellation-X observational program. Adding a…
Searches for physics beyond the Standard Model of particle physics are performed at accelerators worldwide. Although having poorer detection capabilities and large beam uncertainties, ultra high energy cosmic ray (UHECR) experiments present…
Binary systems containing at least one radiopulsar are excellent laboratories to test several aspects of fundamental physics like matter properties in conditions of extreme density and theories of gravitation like the Einstein's General…
Neutron stars are powerful probes into the extremes of physics. In this chapter, we will discuss how observations of neutron stars, either in isolation or in binaries, can be leveraged to test general relativity and constrain competing…
Understanding dense matter under extreme conditions is one of the most fundamental puzzles in modern physics. Complex interactions give rise to emergent, collective phenomena. While nuclear experiments and Earth - based colliders provide…
Ultraluminous X-ray sources (ULXs) represent an extreme class of accreting compact objects: from the identification of some of the accretors as neutron stars to the detection of powerful winds travelling at 0.1-0.2 c, the increasing…
Nuclear spectroscopy is the only instrumentation that provides bulk geochemical constraints at depth (up to one meter in the surface). These instruments identify and quantify water and other key elements relevant to planetary exploration,…
Neutron stars are one of the most extreme objects in the universe, with densities that can exceed those of atomic nuclei and gravitational fields that are among the strongest known. Theoretical and observational research on neutron stars…
The astrophysical neutrinos recently discovered by the IceCube neutrino telescope have the highest detected neutrino energies --- from TeV to PeV --- and travel the longest distances --- up to a few Gpc, the size of the observable Universe.…
General relativity is one of the pillars of modern physics. For decades, the theory has been mainly tested in the weak field regime with experiments in the Solar System and radio observations of binary pulsars. Until 2015, the strong field…
The Probe Of Extreme Multi-Messenger Astrophysics (POEMMA) is designed to observe cosmic neutrinos (CNs) above 20 PeV and ultra-high energy cosmic rays (UHECRs) above 20 EeV over the full sky. The POEMMA mission calls for two identical…
EXIST is being studied as the Black Hole Finder Probe, one of the 3 Einstein Probe missions under NASA's Beyond Einstein program. The major science goals for EXIST include highly sensitive full-sky hard X-ray survey in a very wide energy…
The High-Energy Ray Observatory (HERO) is a space experiment based on a heavy ionization calorimeter for direct study of cosmic rays. The effective geometrical factor of the apparatus varies from 12 to 60 m$^2$sr for protons depending on…
This is a review of high energy neutrino astronomy that might be done with a kilometer-scale detector. The emphasis is on diffuse neutrinos of extragalactic origin and their relation to possible sources of the highest energy cosmic rays,…
The search for rare particles in the cosmic radiation remains one of the main aims of non-accelerator particle astrophysics. Experiments at high altitude allow lower mass thresholds with respect to detectors at sea level or underground. The…
Cosmic electrons, positrons, protons, and antiprotons carry essential information about both astrophysical processes and fundamental physics. Charged particles provide signatures of dark matter annihilation or decay, \emph{in situ} in the…
The properties of matter at ultra-high densities, low temperatures, and with a significant asymmetry between protons and neutrons can be studied exclusively through astrophysical observations of neutron stars. We show that measurements of…
Gamma-ray Astronomy studies cosmic accelerators through their electromagnetic radiation in the energy range between ~100 MeV and ~100 TeV. The present most sensitive observations in this energy band are performed, from space, by the Large…
This paper explores the theoretical implications of quantum gravity by analyzing compact stellar objects, presenting three distinct models that serve as alternatives to traditional black holes. These models are characterized by their…
We review the prospects for probing new physics with neutrino astrophysics. High energy neutrinos provide an important means of accessing physics beyond the electroweak scale. Neutrinos have a number of advantages over conventional…