Recently three dimensional Einstein gravity with AdS geometry has been studied, and pointed out to be described with Chern-Simons theory by Grumiller and Jackiw. While, non-commutative Chern-Simons theory is known to be equivalent to Quantum Hall Effect, through Area Preserving Diffeomorphism by Susskind and others. Conbining these, three dimensional gravity is studied in this paper in the cont...

It is shown that under reasonable assumptions, conservation of angular momentum provides a strong constraint on gravity wave drag feedbacks to radiative perturbations in the middle atmosphere. In the time mean, radiatively induced temperature perturbations above a given altitude z cannot induce changes in zonal mean wind and temperature below z through feedbacks in gravity wave drag alone (assu...

The modified $F(R)$ gravity theory with the function $F(R)=-(1/\beta)\ln(1-\beta R)$ is studied. action at small coupling $\beta$ becomes Einstein--Hilbert action. bound on parameter from local tests $\beta\leq 2\times 10^{-6}$ cm$^2$. We find constant curvature solutions and it was shown that de Sitter space unstable but a solution zero Ricci scalar stable. potential mass of field (scalaron) a...

the results of batch settling tests (bst) are used to investigate settling behavior of solids suspension, which contribute to sizing thickeners. conventional methods in analyzing bst on the basis of visual and graphical procedures lead to sub-optimally sized and selected thickeners. a computational approach based on quantitative analysis of bst can be beneficial. about 300 settling experiments ...

outbreak of 2009 european sovereign debt (leverage) crisis has been one of the most crucial economic events of recent years. accordingly, researchers devoted a great deal of efforts to elucidate origins and consequences of this crisis, particularly focusing on its potential effect on international trade flows. yet in the literature, there have been rare studies on exploring the effects of sover...