The «sovereignty of the imamate» (Siyādat Al-Imāma) of the Jazūliyya-Ghazwāniyya: a sufi alternative to sharifism?

This article details the doctrine of the aṭ-Ṭā’ifa al-Jazūliyya, a populist and politically active Sufi order that dominated Moroccan mysticism throughout the sixteenth century. This doctrine focused on the concept of paradigmatic sainthood (quṭbiyya) and was influenced by two different models of religious authority. The first model saw authority as an acquired property, which was vested in the Sufi shaykh who best mirrored the qualities of the Prophet Muḥammad. The second model conceived of authority as an ascribed property, and saw it as an inborn grace (baraka) that was transmitted via descent through the Prophetic bloodline. In the writings of the Jazūliyya shaykh ‛Abdallah al-Ghazwānī (d. 935/1528-9), both models of authority were seen as part of the «prophetic inheritance» (al-wirātha an-abawiyyd), and were reconciled through the doctrine of the «sovereignty of the imamate» (siyādat al-imāma). In this doctrine, the axial saint of Moroccan Sufism, whom al-Ghazwānī called the jaras or «Bell-saint», stood as the successor (khalīfa) to the Prophet Muhammad and prime interpreter of Islam. He thus took on many of the qualities of the Shi‛ite Imam, an posed a serious challenge to the political leaders of the time.Este artículo analiza la doctrina de la Ṭā’ifa Ŷazūliyya, una orden sufí populista y políticamente activa que dominó el misticismo marroquí a lo largo de todo el siglo xvi. Esta doctrina se centraba en el concepto de santidad paradig mática (quṭbiyya) en el que confluían dos modelos diferentes de autoridad religiosa. El primer modelo vería la autoridad como una propiedad adquirida del šayj Sufi que mejor reproducía las características del Profeta. El segundo modelo veía la autoridad como una propiedad adscrita, la gracia o baraka transmitida por nacimiento dentro del linaje del Profeta. En los escritos del šayj ŷazūlī ‛Abd Allāh al-Gazwānī (935/1528-9) ambos modelos de autoridad se consideran partes de la «herencia profética» reunidos por la doctrina de la «soberanía del imamato». En esta doctrina, el santo axial del sufismo marroquí a quien al-Ghazwānī llama Ŷaras o «campana» se yergue como sucesor (jalīfa) del Profeta y primer intérprete del Islam. Adquirió de esta manera muchas de las cualidades del Imam Šī‛í y planteó serios peligros a los jefes políticos contemporáneos

Graviton emission from a higher-dimensional black hole

We discuss the graviton absorption probability (greybody factor) and the cross-section of a higher-dimensional Schwarzschild black hole (BH). We are motivated by the suggestion that a great many BHs may be produced at the LHC and bearing this fact in mind, for simplicity, we shall investigate the intermediate energy regime for a static Schwarzschild BH. That is, for $(2M)^{1/(n-1)}\omega\sim 1$, where $M$ is the mass of the black hole and $\omega$ is the energy of the emitted gravitons in $(2+n)$-dimensions. To find easily tractable solutions we work in the limit $l \gg 1$, where $l$ is the angular momentum quantum number of the graviton.Comment: 10 pages, 8 figures, references added, typos corrected. Graviton degeneracy factor included; main results remain unchange

Observation of the Presuperfluid Regime in a Two-Dimensional Bose Gas

In complementary images of coordinate-space and momentum-space density in a trapped 2D Bose gas, we observe the emergence of pre-superfluid behavior. As phase-space density $\rho$ increases toward degenerate values, we observe a gradual divergence of the compressibility $\kappa$ from the value predicted by a bare-atom model, $\kappa_{ba}$. $\kappa/\kappa_{ba}$ grows to 1.7 before $\rho$ reaches the value for which we observe the sudden emergence of a spike at $p=0$ in momentum space. Momentum-space images are acquired by means of a 2D focusing technique. Our data represent the first observation of non-meanfield physics in the pre-superfluid but degenerate 2D Bose gas.Comment: Replace with the version appeared in PR

The Reaction-Diffusion Front for A+B→∅A+B \to\emptyset in One Dimension

We study theoretically and numerically the steady state diffusion controlled reaction $A+B\rightarrow\emptyset$, where currents $J$ of $A$ and $B$ particles are applied at opposite boundaries. For a reaction rate $\lambda$, and equal diffusion constants $D$, we find that when $\lambda J^{-1/2} D^{-1/2}\ll 1$ the reaction front is well described by mean field theory. However, for $\lambda J^{-1/2} D^{-1/2}\gg 1$, the front acquires a Gaussian profile - a result of noise induced wandering of the reaction front center. We make a theoretical prediction for this profile which is in good agreement with simulation. Finally, we investigate the intrinsic (non-wandering) front width and find results consistent with scaling and field theoretic predictions.Comment: 11 pages, revtex, 4 separate PostScript figure

Experimental studies of equilibrium vortex properties in a Bose-condensed gas

We characterize several equilibrium vortex effects in a rotating Bose-Einstein condensate. Specifically we attempt precision measurements of vortex lattice spacing and the vortex core size over a range of condensate densities and rotation rates. These measurements are supplemented by numerical simulations, and both experimental and numerical data are compared to theory predictions of Sheehy and Radzihovsky [17] (cond-mat/0402637) and Baym and Pethick [25] (cond-mat/0308325). Finally, we study the effect of the centrifugal weakening of the trapping spring constants on the critical temperature for quantum degeneracy and the effects of finite temperature on vortex contrast.Comment: Fixed minor notational inconsistencies in figures. 12 pages, 8 figure

Observation of Vortex Pinning in Bose-Einstein Condensates

We report the observation of vortex pinning in rotating gaseous Bose-Einstein condensates (BEC). The vortices are pinned to columnar pinning sites created by a co-rotating optical lattice superimposed on the rotating BEC. We study the effects of two different types of optical lattice, triangular and square. With both geometries we see an orientation locking between the vortex and the optical lattices. At sufficient intensity the square optical lattice induces a structural cross-over in the vortex lattice.Comment: 4 pages, 6 figures. Replaced by final version to appear in Phys. Rev. Let

Vortex Proliferation in the Berezinskii-Kosterlitz-Thouless Regime on a Two-Dimensional Lattice of Bose-Einstein Condensates

We observe the proliferation of vortices in the Berezinskii-Kosterlitz-Thouless regime on a two-dimensional array of Josephson-coupled Bose-Einstein condensates. As long as the Josephson (tunneling) energy J exceeds the thermal energy T, the array is vortex free. With decreasing J/T, vortices appear in the system in ever greater numbers. We confirm thermal activation as the vortex-formation mechanism and obtain information on the size of bound vortex pairs as J/T is varied

Fast-diffusion mean-field theory for k-body reactions in one dimension

We derive an improved mean-field approximation for k-body annihilation reactions kA --> inert, for hard-core diffusing particles on a line, annihilating in groups of k neighbors with probability 0 < q <= 1. The hopping and annihilation processes are correlated to mimic chemical reactions. Our new mean-field theory accounts for hard-core particle properties and has a larger region of applicability than the standard chemical rate equation especially for large k values. Criteria for validity of the mean-field theory and its use in phenomenological data fits are derived. Numerical tests are reported for k=3,4,5,6.Comment: 16 pages, TeX (plain

Annotated Computer Output for Analyses of Unbalanced Data: SAS GLM

41 pages, 1 article*Annotated Computer Output for Analyses of Unbalanced Data: SAS GLM* (Searle, S. R.; Henderson, H. V.) 41 page

On Deriving the Inverse of a Sum of Matrices

21 pages, 1 article*On Deriving the Inverse of a Sum of Matrices* (Henderson, H. V.; Searle, S. R.) 21 page