Related papers: Stringent neutron-star limits on large extra dimen…
Neutron stars are among the most fascinating astrophysical sources, being characterized by strong gravity, densities about the nuclear one or even above, and huge magnetic fields. Their observational signatures can be extremely diverse…
Ever since the discovery of neutron stars it has been realized that they serve as probes of a physical regime that cannot be accessed in laboratories: strongly degenerate matter at several times nuclear saturation density. Existing nuclear…
First results of numerical simulations are presented which compute the dynamical evolution of a neutron star with a mass slightly below the minimum stable mass by means of a new implicit (general relativistic) hydrodynamic code. We show…
Core-collapse supernovae emit on the order of 3x10^53 ergs in high-energy neutrinos over a time of order 10 seconds, and so decrease their mass by about 0.2 solar mass. If the explosion is nearly spherically symmetric, there will be little…
Immediately after they are born, neutron stars are characterized by an entropy per baryon of order unity and by the presence of trapped neutrinos. If the only hadrons in the star are nucleons, these effects slightly reduce the maximum mass…
We have proposed that the cosmic ray spectrum "knee", the steepening of the cosmic ray spectrum at energy $E \gsim 10^{15.5}$ eV, is due to "new physics", namely new interactions at TeV cm energies which produce particles undetected by the…
Galactic supernova remnants (SNRs) are thought to accelerate cosmic rays (CRs) to several PeV energies, but this has yet to be confirmed as general behavior. Although several sources show ~100 TeV gamma rays, their hadronic origin is…
Increasing observational evidence gathered especially in X-rays and gamma-rays during the course of the last few years support the notion that Supernova remnants (SNRs) are Galactic particle accelerators up to energies close to the ``knee''…
The explosion of ultra-stripped stars in close binaries may explain new discoveries of weak and fast optical transients. We have demonstrated that helium star companions to neutron stars (NSs) may evolve into naked metal cores as low as…
High energy cosmic ray experiments have identified an excess from the region of the Galactic Plane in a limited energy range around $10^{18}$ eV (EeV). This is very suggestive of neutrons as candidate primaries, because the directional…
Matter ejected from the magnetar crust during giant flares (GFs) may undergo $r$-process nucleosynthesis, producing short-lived optical transients termed "novae breves". Although intrinsically much fainter than kilonovae from compact binary…
Neutrinos mix and have mass differences, so decays from one to another must occur. But how fast? The best direct limits on non-radiative decays, based on solar and atmospheric neutrinos, are weak, $\tau \gtrsim 10^{-3}$ s ($m$/eV) or much…
We discuss the possibility that the sources for gamma ray bursts are hot neutron stars at cosmological distance scales. The temperature of such stars would be $T \sim 1 \MeV$. Such hot stars can produce an electromagnetic blast wave…
Astronomy at the highest energies observed must be performed by studying neutrinos rather than photons because the universe is opaque to photons of these energies. By making observations of neutrinos with energies above 10 EeV one can…
Latest general relativistic simulations for merger of binary neutron stars with realistic equations of state (EOSs) show that a hypermassive neutron star of an ellipsoidal figure is formed after the merger if the total mass is smaller than…
Stable particle dark matter may well originate during the decay of long-lived relic particles, as recently extensively examined in the cases of the axino, gravitino, and higher-dimensional Kaluza-Klein (KK) graviton. It is shown that in…
A procedure to derive bounds on coupling strengths of exotic particles to nucleons from the neutrino signal of supernovae is outlined. The analysis is based on a model independent calculation for the emissivities for the exotic, detailed…
Supernova neutrinos are crucially important to probe the final phases of massive star evolution. As is well known from observations of SN1987A, neutrinos provide information on the physical conditions responsible for neutron star formation…
Isolated ideal neutron stars (NS) of age $>10^9$ yrs exhaust thermal and rotational energies and cool down to temperatures below $\mathcal{O}(100)$ K. Accretion of particle dark matter (DM) by such NS can heat them up through kinetic and…
Ultra-high energy cosmic neutrinos are incisive probes of both astrophysical sources and new TeV-scale physics. Such neutrinos would create extensive air showers deep in the atmosphere. The absence of such showers implies upper limits on…