We suggest pump-probe spectroscopy to study pair correlations that determine the many-body dynamics in weakly interacting, dilute ultracold gases. A suitably chosen, short laser pulse depletes the pair density locally, creating a "hole" in the electronic ground state. The dynamics of this nonstationary pair density is monitored by a time-delayed probe pulse. The resulting transient signal allow...

We have studied the temperature dependent phonon emission rate P(T) of a strongly interacting (r(s) > or =22) dilute 2D GaAs hole system using a standard carrier heating technique. In the still poorly understood metallic state, we observe that P(T) changes from P(T) approximately T5 to P(T) approximately T7 above 100 mK, indicating a crossover from screened piezoelectric (PZ) coupling to screen...

Here n, p denote the electron, hole density, respectively Jn, Jp the electron, hole current, μ the related mobilities, R the recombination/generation. The Poisson equation relates the electrostatic potential u to the total charge density (D is the net doping concentration, ε is the dielectric permittivity). Contact models result in different boundary conditions. For existence and uniqueness (cl...

It has been proposed that a black hole horizon should generate Hawking radiation. In order to test this theory, we have created a narrow, low density, very low temperature atomic Bose-Einstein condensate, containing an analog black hole horizon and an inner horizon, as in a charged black hole. We observe Hawking radiation emitted by the black hole. This is the output of the black hole laser. We...

The observed properties of supermassive black holes suggest a fundamental link between their assembly and the formation of their host spheroids. We model the growth and activity of black holes in galaxies using ΛCDM cosmological hydrodynamic simulations by following the evolution of the baryonic mass component in galaxy potential wells. We find that the observed steep relation between black hol...

We simulate the accretion of high-density dwarf galaxies by low-density giant galaxies, using models that contain both power-law central density cusps and central point masses representing supermassive black holes. The final density profiles of the merger remnants are always similar to the initial density profile of the giant galaxy, for two reasons. 1. The density of the dwarf galaxy is reduce...

Primordial black hole formation by cosmic string collapse is reconsidered when the winding number of the string is larger than the unity. The line energy density of the multiple winding string becomes greater than that of the single winding string so that the probability of the black hole formation by the string collapse during the loop oscillation would be strongly enhanced. Although the produ...

We present the transport and capacitance measurements of 10 nm wide GaAs quantum wells with hole densities around the critical point of the 2D metal-insulator transition (critical density p(c) down to 0.8 × 10(10)/cm2, r(s) ∼ 36). For metallic hole density p(c) < p < p(c) + 0.15 × 10(10)/cm2, a reentrant insulating phase (RIP) is observed between the ν = 1 quantum Hall state and the zero-field ...

Second order perturbation theory and a Lipkin-Nogami scheme combined with an exact Monte Carlo projection after variation are applied to compute the ground-state energy of 6 ≤ N ≤ 210 electron-hole pairs confined in a parabolic two-dimensional quantum dot. The energy shows nice scaling properties as N or the confinement strength is varied. A crossover from the high-density electron-hole phase t...