Field Studies of the Archean in Grand Canyon

The oldest rocks of Arizona which form the precipitous walls of the inner or granite gorge of the Grand Canyon have never received the intensive study that has been given to their counterparts over the great northeastern plains of Canada, in the mountains of Scandinavia or on the rolling expanses of Finland. The metamorphosed rocks standing in places on end under the wedge of the Grand Canyon series of sediments (Algonkian) and elsewhere under the mantle of Paleozoic sediments are known as the Vishnu schist. To J.W. Powell these were known as the “Grand Canyon schists” of tentative “Eozoic” age. C.D. Walcott who proposed the term Vishnu from the occurrence beneath Vishnu temple in the Grand Canyon classified them as “bedded, sedimentary, unconformable, pre-Unkar (Lower Grand Canyon series) strata.

A hybrid model approach for strange and multi-strange hadrons in 2.76 A TeV Pb+Pb collisions

Using the VISHNU hybrid model, we calculate the multiplicity, spectra, and elliptic flow of $\Lambda$, $\Xi$ and $\Omega$ in 2.76 A TeV Pb+Pb collisions. Comparisons between our calculations and the ALICE measurements show that the model generally describes the soft hadron data of these strange and multi-strange hadrons at several centrality bins. Mass ordering of elliptic flow among $\pi$, K, p, $\Lambda$, $\Xi$ and $\Omega$ has also been studied and discussed. With a nice description of the particle yields, we explore chemical and thermal freeze-out of various hadrons species at the LHC within the framework of the VISHNU hybrid model.Comment: version 2: with several references added, published in PR

Spectra and elliptic flow of (multi-)strange hadrons at RHIC and LHC within viscous hydrodynamics+hadron cascade hybrid model

Using the (2+1)-dimensional ultrarelativistic viscous hydrodynamics+hadron cascade, VISHNU, hybrid model, we study the $p_{\rm T}$-spectra and elliptic flow of $\Lambda$, $\Xi$, and $\Omega$ in Au+Au collisions at $\sqrt{s_{NN}}$=200 GeV and in Pb+Pb collisions at $\sqrt{s_{NN}}$=2.76 TeV. Comparing our model results with the data measurements, we find that the VISHNU model gives general descriptions of the measurements of these strange and multi-strange hadrons at several centrality classes at RHIC and LHC. Mass ordering of elliptic flow $v_{2}$ among $\pi$, $K$, $p$, $\Lambda$, $\Xi$, and $\Omega$ are further investigated and discussed at the two collision systems. We find, at both RHIC and LHC, the $v_{2}$ mass ordering among $\pi$, $K$, $p$, and $\Omega$ are fairly reproduced within the VISHNU hybrid model, and more improvements are needed to implement for well describing the $v_{2}$ mass ordering among $p$, $\Lambda$, and $\Xi$.Comment: revise the draft according to the reviewers` comments, 7 pages, 5 figure

Die Theologie Vishnus auf der Grundlage religiöser Erfahrungen der Hindus

Im Rigveda, der altindischen Sammlung von Gesängen des Heiligen, heißt es über Vishnu: "Mögen die Götter uns vor dem Ort, von dem aus Vishnu über die sieben Bereiche der Erde schritt, bewahren. Vishnu schritt über (das Universum); dreimal setzte er seinen Fuß auf; die Welt war in seinem Staub eingehüllt; Vishnu, der unbesiegbare Bewahrer, den niemand täuscht, tat drei Schritte; von da an setzte er seine hohen Gesetze in Kraft." Vishnu durchmaß die Welt mit drei Schritten und richtete seine Ordnung, seinen Dharma, auf. Welches aber war der Sinn des Dreischritts? Von Vishnu heißt es dazu im Rigveda: "Welcher (sc. Vishnu) wahrhaftig allein die Dreiheit Erde, Himmel und Lebewesen trägt."Und das, was er bewahrt, ist ein Dreifaches: Erde, Himmel und die lebenden Wesen. Aber der entscheidende Grund für Lobwürdigkeit Vishnus besteht denn auch darin, daß er nicht nur seine Werke bewahrt, sondern durch seinen Dreischritt überhaupt erst Lebensräume für alle Wesen geschaffen hat. Daß Lebensraumbeschaffung der Sinn der drei Schritte war, wird an anderer Stelle nochmals betont: "Über diese Erde schrittt mit mächtigem Tritt Vishnu, bereit sie als Heim dem Menschen zu geben. / Seinem Schutz vertraut das einfache Volk sich an, er, der Edelgeborene, hat ihnen weiträumige Wohnstatt bereitet." Von diesen drei Lebensräumen weiß der rigvedische Sänger sogar zu berichten, daß in ihnen Milch und Honig fließt. Lob sei daher Vishnu "dessen drei Weltenräume voll von Süße sind." Vishnu hat die irdische Welt den Menschen als Paradies erworben, denn süß ist sie, nicht ein Tal der Tränen, des Elends und der Bitterkeit. Süße verweist auf einen Zustand der Zufriedenheit und Erfülltheit. Vishnu erwirbt sich das Vertrauen des einfachen Volks, weil er ihm durch seinen Dreischritt eine erfüllte und gesicherte Existenz verschafft hat.6 In den wenigen rigvedischen Manifestationen Vishnus leuchtet bereits ein grundlegender Wesenszug Vishnus auf: Er liebt und umsorgt die irdische Welt. ..

Narasimha, the Supreme Lord of the Middle: The Avatāra and Vyūha Correlation in the Purāṇas, Archaeology and Religious Practice

Avatāra is a theologically significant term associated with Vishnu, due to his role as protector and maintainer of balance between evil and good in the universe. Hence, each avatāra of Vishnu indicates a divinely inspired cosmic role of Vishnu. However, the incarnation of Narasimha is significant, because this incarnation is a dual representation of the God Vishnu within the creation. It is this dual representation that is central to the projection of Narasimha as the Supreme Lord in Hinduism. Therefore, this paper examines the dual roles of Vishnu as the avatāra and vyūha in his interaction with the universe in his incarnation as Narasimha in texts, religious practice and iconic representation

The iEBE-VISHNU code package for relativistic heavy-ion collisions

The iEBE-VISHNU code package performs event-by-event simulations for relativistic heavy-ion collisions using a hybrid approach based on (2+1)-dimensional viscous hydrodynamics coupled to a hadronic cascade model. We present the detailed model implementation, accompanied by some numerical code tests for the package. iEBE-VISHNU forms the core of a general theoretical framework for model-data comparisons through large scale Monte-Carlo simulations. A numerical interface between the hydrodynamically evolving medium and thermal photon radiation is also discussed. This interface is more generally designed for calculations of all kinds of rare probes that are coupled to the temperature and flow velocity evolution of the bulk medium, such as jet energy loss and heavy quark diffusion.Comment: 47 pages, 21 figures. Manuscript was accepted by Computer Physics Communication

Archean detrital zircons in the Proterozoic Vishnu Schist of the Grand Canyon, Arizona : implications for crustal architecture and Nuna reconstructions

U-Pb dating of 1035 detrital zircons from twelve spatially-distributed samples of the Paleoproterozoic Vishnu Schist reveals a bimodal 207Pb/ 206Pb age probability diagram with peaks at 1.8 Ga and 2.5 Ga. Surprisingly, only 13% of detrital zircon ages overlap with the published depositional age range of 1750–1741 Ma. The similarity of the age distributions in all samples constrains possible suturing of crustal blocks to pre-Vishnu Schist deposition rather than during the peak 1710-1680 Ma deformation. Of all grains analyzed, 15% overlap at 2σ with the 1.84 ± 1 Ga Elves Chasm orthogneiss of western Grand Canyon. This supports field evidence that Vishnu Schist was deposited on 1.84 Ga arc basement rather than in a juvenile 1.75 Ga arc setting. Archean grains of 3.8–2.5 Ga comprise 30% of all grains. A comparison of the \u3e 2.2 Ga ages from the Vishnu Schist (495 grains) with compilations of zircon ages from other cratons does not support provenances in the Wyoming, South China, or Siberian cratons; instead sources may be located in Gawler craton of Australia, North China craton, or Antarctica. If the detrital zircons were far-traveled, this is a new constraint for viable reconstructions of the Nuna supercontinent. However, given the high percentage of pre-1.8 Ga zircons, unexposed proximal basement sources are more likely, resulting in a model by which Vishnu sediments were derived from Mojave crust that consists of Archean and 1.9-1.8 Ga crust, now in the subsurface, that was unroofed during Vishnu deposition