Analytic study of mass segregation around a massive black hole (2009)
Keshet, Uri, Hopman, Clovis, Alexander, Tal
We analyze the distribution of stars of arbitrary mass function g(m) around a massive black hole (MBH). Unless g is strongly dominated by light stars, the steady-state distribution function...
Magnetic field evolution in relativistic unmagnetized collisionless shocks (2008)
Keshet, Uri, Katz, Boaz, Spitkovsky, Anatoly, Waxman, Eli
We study relativistic unmagnetized collisionless shocks using unprecedentedly large particle-in-cell simulations of two-dimensional pair plasma. High energy particles accelerated by the shock are...
Asymptotic Spectroscopy of Rotating Black Holes (2007)
We calculate analytically the transmission and reflection amplitudes for waves incident on a rotating black hole in d=4, analytically continued to asymptotically large, nearly imaginary frequency....
Analytic Study of Rotating Black-Hole Quasinormal Modes (2007)
A Bohr-Sommerfeld equation is derived for the highly-damped quasinormal mode frequencies omega(n>>1) of rotating black holes. It may be written as 2\int_C(p_r+ip_0)dr=(n+1/2)h, where p_r is the...
Analytical Study of Diffusive Relativistic Shock Acceleration (2006)
Particle acceleration in relativistic shocks is studied analytically in the test-particle, small-angle scattering limit, for an arbitrary velocity-angle diffusion function D. Accurate analytic...
Self-Similar Collisionless Shocks (2006)
Katz, Boaz, Keshet, Uri, Waxman, Eli
Observations of gamma-ray burst afterglows suggest that the correlation length of magnetic field fluctuations downstream of relativistic non-magnetized collisionless shocks grows with distance from...
Selection Rules for Black-Hole Quantum Transitions (2005)
We suggest that quantum transitions of black holes comply with selection rules, analogous to those of atomic spectroscopy. In order to identify such rules, we apply Bohr's correspondence principle to...
Survival Probabilities of History-Dependent Random Walks (2005)
We analyze the dynamics of random walks with long-term memory (binary chains with long-range correlations) in the presence of an absorbing boundary. An analytically solvable model is presented, in...
Intermediate Asymptotics of the Kerr Quasinormal Spectrum (2005)
We study analytically the quasinormal mode spectrum of near-extremal (rotating) Kerr black holes. We find an analytic expression for these black-hole resonances in terms of the black-hole physical...
The spectrum of particles accelerated in relativistic, collisionless shocks (2004)
We analytically study diffusive particle acceleration in relativistic, collisionless shocks. We find a simple relation between the spectral index s and the anisotropy of the momentum distribution...
Searching for Intergalactic Shocks with the SKA (2004)
Keshet, Uri, Waxman, Eli, Loeb, Abraham
Strong intergalactic shocks are a natural consequence of structure formation in the universe. These shocks are expected to deposit large fractions of their energy in relativistic electrons (xi_e~0.05...
Phase-Transition in Binary Sequences with Long-Range Correlations (2003)
Motivated by novel results in the theory of correlated sequences, we analyze the dynamics of random walks with long-term memory (binary chains with long-range correlations). In our model, the...
The Case for a Low Extragalactic Gamma-ray Background (2003)
Keshet, Uri, Waxman, Eli, Loeb, Abraham
Measurements of the diffuse extragalactic gamma-ray background (EGRB) are complicated by a strong Galactic foreground. Estimates of the EGRB flux and spectrum, obtained by modeling the Galactic...
Gamma Rays from Intergalactic Shocks (2003)
Keshet, Uri, Waxman, Eli, Loeb, Abraham, Springel, Volker, Hernquist, Lars
Gamma-Rays from Intergalactic Shocks (2002)
Keshet, Uri, Waxman, Eli, Loeb, Abraham, Springel, Volker, Hernquist, Lars
Structure formation in the intergalactic medium (IGM) produces large-scale, collisionless shock waves, where electrons can accelerate to highly relativistic energies. Such electrons can Compton...