oalib

Publish in OALib Journal

ISSN: 2333-9721

APC: Only $99

Submit

Any time

2019 ( 73 )

2018 ( 484 )

2017 ( 508 )

2016 ( 751 )

Custom range...

Search Results: 1 - 10 of 325651 matches for " S Friedman "
All listed articles are free for downloading (OA Articles)
Page 1 /325651
Display every page Item
‘We Met the Enemy and He is Us’: Domestic Politics and South Africa’s Role in Promoting African Democracy
S Friedman
African Journal of International Affairs , 2008,
Abstract: South Africa’s post-apartheid foreign policy has disappointed scholars and activists who expected the post-apartheid state to promote democracy and human rights in Africa and the world, and who complain that it has failed to fulfill that promise. This paper examines South Africa’s role in democracy promotion since 1994 and, in particular, the argument that it intended to promote rights and freedoms in Africa but was forced to change its approach by power realities on the continent. It finds this explanation wanting and argues that the core goal of foreign policy of the post-apartheid government was not to promote democracy, but rather, merely to prove white racism wrong. Since 1994, the African National Congress-led government has been aware that much of white opinion, at home and abroad, expects majority ruled African societies to fail. Its prime concern, therefore, has been to refute the prejudice that black Africans cannot run successful societies. It is this concern which has underpinned foreign policy: the aim has been to project Africa as a continent whose states are measuring up to the Northern model of a successful society. Hence, democracy promotion has been only a means to that end, and this is the major factor responsible for its uneven and sporadic application.
Influence of volatile degassing on initial flow structure and entrainment during undersea volcanic fire fountaining eruptions  [PDF]
P. D. Friedman, S. Carey, M. Raessi
Natural Science (NS) , 2012, DOI: 10.4236/ns.2012.412129
Abstract: Release of dissolved volatiles during submarine fire fountaining eruptions can profoundly influence the buoyancy flux at the vent. Theoretical considerations indicate that in some cases buoyant magma can be erupted prior to fragmentation (~75% vesicle volume threshold). Laboratory simulations using immiscible fluids of contrasting density indicate that the structure of the source flow at the vent depends critically on the relative magnitudes of buoyancy and momentum fluxes as reflected in the Richardson number (Ri). Analogue laboratory experiments of buoyant discharges demonstrate a variety of complex flow structures with the potential for greatly enhanced entrainment of surrounding seawater. Such conditions are likely to favor a positive feedback between phreatomagmatic explosions and volatile degassing that will contribute to explosive volcanism. The value of the Richardson number for any set of eruption parameters (magma discharge rate and volatile content) will depend on water depth as a result of the extent to which the exsolved volatile components can expand.
The scalar complex potential of the electromagnetic field
Y. Friedman,S. Gwertzman
Physics , 2009,
Abstract: In this paper, we define a scalar complex potential $\mathcal{S}$ for an arbitrary electromagnetic field. This potential is a modification of the two scalar potential functions introduced by E. T. Whittaker. By use of a complexified Minkowski space $M$, we decompose the usual Lorentz group representation on $M$ into a product of two commuting new representations. These representations are based on the complex Faraday tensor. For a moving charge and for any observer, we obtain a complex dimensionless scalar which is invariant under one of our new representations. The scalar complex potential is the logarithm of this dimensionless scalar times the charge value. We define a conjugation on $M$ which is invariant under our representation. We show that the Faraday tensor is the derivative of the conjugate of the gradient of the complex potential. The real part of the Faraday tensor coincides with the usual electromagnetic tensor of the field. The potential $\mathcal{S}$, as a complex-valued function on space-time, is described as an integral over the distribution of the charges generating the electromagnetic field. This potential is like a wave function description of the field. If we chose the Bondi tetrad (called also Newman-Penrose basis) as a basis on $M$, the components of the Faraday vector at each point may be derived from $\mathcal{S}$ by $ F_j=E_j+iB_j={\partial}^\nu (\alpha_j)_\nu^\lambda{\partial}_\lambda \mathcal{S}$, where $(\alpha_j)$ are the known $\alpha$-matrices of Dirac. This fact indicates that our potential may build a "bridge" between classical and quantum physics.
Feasibility guidelines for kaonic-atom experiments with ultra-high-resolution X-ray spectrometry
E. Friedman,S. Okada
Physics , 2013, DOI: 10.1016/j.nuclphysa.2013.07.005
Abstract: Recent studies of strong interaction effects in kaonic atoms suggest that analysing so-called `lower' and `upper' levels in the same atom could separate one-nucleon absorption from multinucleon processes. The present work examines the feasibility of direct measurements of upper level widths in addition to lower level widths in future experiments, using superconducting microcalorimeter detectors. About ten elements are identified as possible candidates for such experiments, all of medium-weight and heavy nuclei. New experiments focused on achieving good accuracy for widths of such pairs of levels could contribute significantly to our knowledge of the $K^-$-nucleon interaction in the nuclear medium.
Regularized determinants of the Laplacian for cofinite Kleinian groups with finite-dimensional unitary representations
Joshua S. Friedman
Mathematics , 2006, DOI: 10.1007/s00220-007-0330-3
Abstract: For cofinite Kleinian groups (or equivalently, finite-volume three-dimensional hyperbolic orbifolds) with finite-dimensional unitary representations, we evaluate the regularized determinant of the Laplacian using W. Muller's regularization. We give an explicit formula relating the determinant to the Selberg zeta-function.
The Selberg Trace Formula for Hecke operators on cocompact Kleinian groups
Joshua S. Friedman
Mathematics , 2007,
Abstract: We compute the Selberg trace formula for Hecke operators (also called the trace formula for modular correspondences) in the context of cocompact Kleinian groups with finite-dimentional unitary representations. We give some applications to the distribution of Hecke eigenvalues, and give an analogue of Huber's theorem.
The Selberg trace formula and Selberg zeta-function for cofinite Kleinian groups with finite-dimensional unitary representations
Joshua S. Friedman
Mathematics , 2004, DOI: 10.1007/s00209-005-0806-9
Abstract: For cofinite Kleinian groups, with finite-dimensional unitary representations, we derive the Selberg trace formula. As an application we define the corresponding Selberg zeta-function and compute its divisor, thus generalizing results of Elstrodt, Grunewald and Mennicke to non-trivial unitary representations. We show that the presence of cuspidal elliptic elements sometimes adds ramification point to the zeta function. In fact, if D is the ring of Eisenstein integers, then the Selberg zeta-function of PSL(2,D) contains ramification points and is the sixth-root of a meromorphic function.
Analogues of the Artin factorization formula for the automorphic scattering matrix and Selberg zeta-function associated to a Kleinian group
Joshua S. Friedman
Mathematics , 2007,
Abstract: For Kleinian groups acting on hyperbolic three-space, we prove factorization formulas for both the Selberg zeta-function and the automorphic scattering matrix. We extend results of Venkov and Zograf from Fuchsian groups, to Kleinian groups, and we give a proof that is simple and extendable to more general groups.
The Selberg Trace Formula and Selberg Zeta-Function for Cofinite Kleinian Groups with Finite Dimensional Unitary Representations: Stony Brook University PhD Thesis
Joshua S. Friedman
Mathematics , 2006,
Abstract: For cofinite Kleinian groups, with finite-dimensional unitary representations, we derive the Selberg trace formula. As an application we define the corresponding Selberg zeta-function and compute its divisor, thus generalizing results of Elstrodt, Grunewald and Mennicke to non-trivial unitary representations. We show that the presence of cuspidal elliptic elements sometimes adds ramification point to the zeta function. In fact, if D is the ring of Eisenstein integers, then the Selberg zeta-function of PSL(2,D) contains ramification points.
On the minimal distance between elliptic fixed points for geometrically-finite Fuchsian groups
Joshua S. Friedman
Mathematics , 2014,
Abstract: Let $\Gamma$ be a geometrically-finite Fuchsian group acting on the upper half plane $\hh.$ Let $\E$ denote the set of elliptic fixed points of $\Gamma$ in $\hh.$ We give a lower bound on the minimal hyperbolic distance between points in $\E.$ Our bound depends on a universal constant and the length of the smallest closed geodesic on $\Gamma \backslash \hh.$
Page 1 /325651
Display every page Item


Home
Copyright © 2008-2017 Open Access Library. All rights reserved.