Indonesia in the 21st Century: Environment at the Crossroads

This paper aims to look at Indonesia's state of the environment at the end of the second 25 year Long Term Plan (Pembangunan Jangka Panjang Kedua -PJPT II), and also aims to signal a warning for Indonesia to put things in order and not to carry on with "business as usual". The "warning" stems from the concept of the Precautionary Principle which focuses on a worst case scenario and from there makes three appeals -the need to halt pollution in advance of concrete knowledge about its impacts, the need to take responsibility for pollution that is occurring, and like this paper itself, appeals to the idea that "common sense" must prevail if development is to be sustainable

Two-component Bose gases with one-body and two-body couplings

We study the competition between one-body and two-body couplings in weakly-interacting two-component Bose gases, in particular as regards field correlations. We derive the meanfield theory for both ground state and low-energy pair excitations in the general case where both one-body and two-body couplings are position-dependent and the fluid is subjected to a state-dependent trapping potential. General formulas for phase and density correlations are also derived. Focusing on the case of homogeneous systems, we discuss the pair-excitation spectrum and the corresponding excitation modes, and use them to calculate correlation functions, including both quantum and thermal fluctuation terms. We show that the relative phase of the two components is imposed by that of the one-body coupling, while its fluctuations are determined by the modulus of the one-body coupling and by the two-body coupling. One-body coupling and repulsive two-body coupling cooperate to suppress relative-phase fluctuations, while attractive two-body coupling tends to enhance them. Further applications of the formalism presented here and extensions of our work are also discussed.Comment: published versio

Entanglement entropy for the long range Ising chain

We consider the Ising model in a transverse field with long-range antiferromagnetic interactions that decay as a power law with their distance. We study both the phase diagram and the entanglement properties as a function of the exponent of the interaction. The phase diagram can be used as a guide for future experiments with trapped ions. We find two gapped phases, one dominated by the transverse field, exhibiting quasi long range order, and one dominated by the long range interaction, with long range N\'eel ordered ground states. We determine the location of the quantum critical points separating those two phases. We determine their critical exponents and central-charges. In the phase with quasi long range order the ground states exhibit exotic corrections to the area law for the entanglement entropy coexisting with gapped entanglement spectra.Comment: 5 pages, all comments welcom

Investigation of afterburner combustion screech and methods of its control at high combustor pressure levels

Control of high pressure combustion screech in afterburne