About the physics concept the gymnastics apparatus Rings gymnastics A Roman ring , in theoretical physics , is a configuration of wormhole s where for each individual wormhole the time difference across its mouths is such that it may not allow a closed timelike curve CTC , or closed time loop . If these wormholes and their mouths are arranged in a suitable configuration, a closed time loop will be again possible. For example, an Earth Moon wormhole whose far end is 0.5 seconds in the Relativity of simultaneity past will not violate causality , since information sent to the far end via the wormhole and back through normal space will still arrive back on Earth 0.5 1 0.5 seconds after it was transmitted but an additional wormhole in the other direction will allow information to arrive back on Earth 1 second before it was transmitted. Semiclassical gravity Semiclassical approaches to incorporating quantum effects into general relativity seem to show that the chronology protection conjecture postulated by physicist Stephen Hawking fails to prevent the formation of such rings, although some experts such as Matt Visser feel that there are reasons to think the semiclassical approach is unreliable here, and that a full theory of quantum gravity will likely uphold chronology protection. Image Roman ring with one wormhole.png frame left A wormhole with no CTC Image Roman ring with two wormholes.png frame left A Roman ring with two wormholes Image Roman ring with four wormholes.png frame left A Roman ring with four wormholes br style clear both References cite arxiv author Visser, Matt title Traversable wormholes the Roman ring eprint gr qc 9702043 cite arxiv author Visser, Matt title van Vleck determinants traversable wormhole spacetimes eprint gr qc 9311026 Category General relativity Category Time travel Category Wormhole theory relativity stub es Anillo Romano ... more details
File Jiri Tuma a Vlastimil Klima.jpg right thumb Vlastimil Kl ma on the right during a lecture on hash functions Candidate of Sciences Czech Republic RNDr. Vlastimil Kl ma born February 19, 1957 is a Czech people Czech cryptologist and computer security expert. He is an author of several works in the field of cryptographic hash function s and digital signature s. After he published one of the most efficient algorithm s for finding hash collision s in the MD5 function, ref Vlastimil Klima http eprint.iacr.org 2005 075 Finding MD5 Collisions a Toy For a Notebook , Cryptology ePrint Archive Report 2005 075, 5 Mar 2005, revised 8 Mar 2005. Retrieved July 27, 2008. ref ref Vlastimil Klima http eprint.iacr.org 2006 105 Tunnels in Hash Functions MD5 Collisions Within a Minute , Cryptology ePrint Archive Report 2006 105, 18 Mar 2006, revised 17 Apr 2006. Retrieved July 27, 2008. ref he designed his own concept of a hash function, which entered the NIST hash function competition under the name Blue Midnight Wish . ref cite web url http www.item.ntnu.no people personalpages fac danilog blue midnight wish title blue midnight wish accessdate 10 November 2008 author Svein Johan Knapskog coauthors Danilo Gligoroski, Vlastimil Klima, Mohamed El Hadedy, J rn Amundsen, Stig Frode Mj lsnes date November 4, 2008 ref External links http cryptography.hyperlink.cz Personal pages of Vlastimil Klima References Reflist Persondata Metadata see Wikipedia Persondata . NAME Klima, Vlastimil ALTERNATIVE NAMES SHORT DESCRIPTION DATE OF BIRTH February 19, 1957 PLACE OF BIRTH DATE OF DEATH PLACE OF DEATH DEFAULTSORT Klima, Vlastimil Category 1957 births Category Living people Category People associated with computer security Category Modern cryptographers Category People from Prague Category Czech scientists Czech bio stub cs Vlastimil Kl ma sk Vlastimil Kl ma ... more details
The Kerr CFT correspondence is an extension of the AdS CFT correspondence or String theory Gauge gravity duality gauge gravity duality to rotating black hole s which are described by the Kerr metric . ref cite arxiv last1 Bredberg first1 Irene last2 Keeler first2 Cynthia last3 Lysov first3 Vyacheslav last4 Strominger first4 Andrew eprint 1103.2355 title Cargese Lectures on the Kerr CFT Correspondence year 2011 class hep th ref The duality works for black holes whose event horizon near horizon geometry can be expressed as a product of Anti de Sitter space AdS sub 3 sub and a single compact coordinate. The AdS CFT duality then maps this to a two dimensional conformal field theory the compact coordinate being analogous to the n sphere S sup 5 sup factor in Juan Maldacena Maldacena s original work , from which the correct Black hole thermodynamics Black hole entropy Bekenstein entropy can then be deduced. ref cite web url http www.nonequilibrium.net kerrcft paradigm understand entropy real black holes title Kerr CFT A paradigm to understand the entropy of real black holes? last1 Compere first1 Geoffrey accessdate 23 July 2011 date 24 February 2009 ref The original form of the duality applies to black holes with the maximum value of angular momentum , but it has now been speculatively extended to all lesser values. ref cite arxiv eprint 1004.0996 year 2010 title Hidden Conformal Symmetry of the Kerr Black Hole last1 Castro first1 Alejandro last2 Maloney first2 Alexander last3 Strominger first3 Andrew class hep th ref See also AdS black hole References reflist External links http motls.blogspot.com 2010 04 kerr black hole cft entropy works for.html Kerr black hole the CFT entropy works for all M,J http arxiv4.library.cornell.edu abs 0809.4266 The Kerr CFT correspondence Category String theory Category Conformal field theory Category Black holes Category Thermodynamics ... more details
Tom Bridgeland is a professor of mathematics at the University of Oxford and a Senior Research Fellow at All Souls College, Oxford All Souls College . Previously he was a professor at Sheffield University . He did his PhD at the University of Edinburgh , where he stayed for a post doctoral position. His research interest is algebraic geometry , focusing on properties of derived categories of coherent sheaves on algebraic varieties . He won the Adams Prize in 2007. His most cited papers are on stability conditions, on triangulated categories ref cite arxiv last Bridgeland first Tom eprint math 0212237v3 title Stability conditions on triangulated categories ref and K3 surfaces ref cite arxiv last Bridgeland first Tom eprint math 0307164 title Stability conditions on K3 surfaces ref in the first he defines the idea of a stability condition on a triangulated category , and demonstrates that the set of all stability conditions on a fixed category form a manifold, whilst in the second he describes one connected component of the space of stability conditions on the bounded derived category of coherent sheaves on a complex algebraic K3 surface . References references Persondata Metadata see Wikipedia Persondata . NAME Bridgeland, Tom ALTERNATIVE NAMES SHORT DESCRIPTION DATE OF BIRTH PLACE OF BIRTH DATE OF DEATH PLACE OF DEATH DEFAULTSORT Bridgeland, Tom Category Living people Category British mathematicians Category Adams Prize recipients Category Academics of the University of Sheffield External Links http www.all souls.ox.ac.uk people.php?personid 2079 Official Homepage at All Souls de Tom Bridgeland ... more details
Image logo DChooz.jpg thumb The Double Chooz logo Double Chooz is a long baseline neutrino oscillation experiment in Chooz, Ardennes Chooz , France. Its goal is to measure or set a limit on sub 13 sub , a neutrino oscillation parameter responsible for changing electron neutrino s into other neutrinos. The experiment uses reactors of the Chooz Nuclear Power Plant as a neutrino source. Double Chooz is a successor to the CHOOZ experiment one of its detectors occupies the same site as its predecessor. In November 2011, first results of the experiment were presented at the LowNu conference in Seoul . They hint at a non zero value of sub 13 sub . ref http www.dchooz.org DocDB cgi bin public ShowDocument?docid 3393 Herve de Kerret, First results from the Double Chooz experiment , talk at the LowNu conference, Seoul, November 2011, via http www.doublechooz.org Status and News status and news.php ref Bibliography Cite arxiv author M. Apollonio et al. title Search for neutrino oscillations on a long base line at the CHOOZ nuclear power station year 2003 class hep ex eprint hep ex 0301017 Cite arxiv author M. Goodman, T. Lasserre year 2006 title Double Chooz A Search for the Neutrino Mixing Angle &theta sub 13 sub class hep ex eprint hep ex 0606025 cite journal author P. Huber et al. year 2006 title From double Chooz to triple Chooz neutrino physics at the Chooz reactor complex url http www.iop.org EJ article 1126 6708 2006 05 072 jhep052006072.pdf journal Journal of High Energy Physics volume issue pages doi References Reflist External links http doublechooz.in2p3.fr Public public.php Project Homepage neutrino detectors physics stub Category Neutrino experiments de Double Chooz Experiment fr Double Chooz ... more details
SOBER 128 is a synchronous stream cipher designed by Hawkes and Rose 2003 and is a member of the SOBER cipher SOBER family of cipher s. SOBER 128 was also designed to provide Message authentication code MAC Message authentication code functionality. Watanabe and Furuya 2004 showed a weakness in the MAC generation of SOBER 128 which means an attack could forge a message with probability 2 sup 6 sup . MAC functionality was deleted by Qualcomm from SOBER 128 reference code. SOBER 128 takes a key cryptography key up to 128 bits in length. See also Helix cipher Helix Turing cipher Turing References Dai Watanabe and Soichi Furuya, A MAC Forgery Attack on SOBER 128, FSE 2004. pp472&ndash 482. Philip Hawkes and Greg Rose, Primitive Specification for SOBER 128, IACR ePrint archive, 2003 http eprint.iacr.org 2003 081 . External links https opensource.qualcomm.com index.php?sober128 SOBER 128 page at Qualcomm Open Source Cryptography navbox stream Category Broken stream ciphers Category Stream ciphers crypto stub ... more details
In mathematics , the Kirby Siebenmann class is an element of the fourth cohomology group math e M in H 4 M mathbf Z 2 math which must vanish if a topological manifold M is to have a piecewise linear structure . It is named for Robion Kirby and Larry Siebenmann . See also Hauptvermutung References cite arXiv title Piecewise linear structures on topological manifolds year 2001 version eprint math.AT 0105047 last1 Rudyak first1 Yuli B. class math.AT Cite book url http www.maths.ed.ac.uk aar haupt ks.pdf title Foundational Essays on Topological Manifolds, Smoothings, and Triangulations first Robion C. last Kirby first2 Laurence C. last2 Siebenmann year 1977 isbn 0 691 08191 3 publisher Princeton Univ. Pr. location Princeton, NJ format dead link date June 2010 postscript None Topology of 4 Manifolds by Robion C. Kirby ISBN 0 387 51148 2 topology stub Category Homology theory Category Geometric topology Category Structures on manifolds Category Surgery theory ... more details
Eprint . Reprinted in Charles Sanders Peirce bibliography W Writings of Charles S. Peirce v. 2, pp. 433 8, Peirce Edition Project http www.iupui.edu peirce writings v2 w2 w2 41 v2 41.htm Eprint . ref ... more details
In cryptography , CWC Mode Carter Wegman Block cipher modes of operation CTR mode is an AEAD block cipher modes of operation AEAD block cipher mode of operation that provides both encryption and built in message integrity, similar to CCM and OCB modes. Designed by Tadayoshi Kohno , John Viega and Doug Whiting , NIST is http csrc.nist.gov groups ST toolkit BCM modes development.html currently considering CWC mode for standardization. It combines the use of CTR mode for encryption with an efficient polynomial Carter Wegman MAC . External links http www.zork.org cwc CWC mode home page http eprint.iacr.org 2003 106 CWC A high performance conventional authenticated encryption mode eprint http gladman.plushost.co.uk oldsite AES index.php Implementation of CWC on top of Advanced Encryption Standard AES . Cryptography navbox block Category Block cipher modes of operation Category Authenticated encryption schemes crypto stub ... more details
for Milnor s conjecture about K theory Milnor conjecture In knot theory , the Milnor conjecture says that the slice genus of the math p, q math torus knot is math p 1 q 1 2. math It is in a similar vein to the Thom conjecture . It was first proved by Gauge theory gauge theoretic methods by Peter Kronheimer and Tomasz Mrowka . ref citation title Gauge theory for embedded surfaces, I first1 P. B. last1 Kronheimer authorlink1 Peter Kronheimer first2 T. S. last2 Mrowka journal Topology volume 32 issue 4 year 1993 pages 773 826 doi 10.1016 0040 9383 93 90051 V . ref Jacob Rasmussen later gave a purely combinatorial proof using Khovanov homology , by means of the s invariant . ref cite arxiv eprint math.GT 0402131 title Khovanov homology and the slice genus first Jacob A. last Rasmussen year 2004 . ref References reflist Category Geometric topology Category Knot theory Category 4 manifolds Category Conjectures knottheory stub fr Conjecture de Milnor th orie des n uds ... more details
In cryptography, the common reference string CRS model captures the assumption that a trusted setup in which all involved parties get access to the same string crs taken from some distribution D exists. Schemes Provable security proven secure in the CRS model are secure given that the setup was performed correctly. The common reference string model is a generalization of the common random string model, in which D is the uniform distribution of bit strings. As stated in ref Ran Canetti and Marc Fischlin Universally Composable Commitments Cryptology ePrint Archive Report 2001 055 http eprint.iacr.org 2001 055 link ref , the CRS model is equivalent to the reference string model ref Marc Fischlin, Roger Fischlin Efficient Non malleable Commitment Schemes. CRYPTO 2000 413 431 ref and the public parameters model ref Ivan Damg rd Efficient Concurrent Zero Knowledge in the Auxiliary String Model. EUROCRYPT 2000 418 430 ref . The CRS model has applications in the study of non interactive zero knowledge proof s and universal composability . References references crypto stub Category Cryptographic protocols Category Theory of cryptography ... more details
In mathematics , a Hadamard manifold , named after Jacques Hadamard &mdash sometimes called a Cartan Hadamard manifold , after lie Cartan &mdash is a Riemannian manifold M , g that is complete space complete and simply connected space simply connected , and has everywhere non positive sectional curvature . Examples The real line R with its usual metric is a Hadamard manifold with constant sectional curvature equal to 0. Standard n dimensional hyperbolic space H sup n sup is a Hadamard manifold with constant sectional curvature equal to &minus 1. See also Cartan Hadamard theorem Hadamard space References cite arxiv last Mourougane first Christophe title Interpolation in non positively curved K hler manifolds date 7 Mar 2001 eprint math 0103045 class math.CV Category Riemannian manifolds topology stub fr Vari t de Hadamard ... more details
The singular isothermal sphere SIS profile is the simplest parameterization of the spatial distribution of matter in an Astronomy astronomical system e.g. galaxy galaxies , Galaxy groups and clusters clusters of galaxies , etc. ref cite journal first C. last Keeton year 2002 month June title A Catalog of Mass Models for Gravitational Lensing journal eprint arXiv astro ph 0102341 bibcode 2001astro.ph..2341K accessdate 2008 06 01 ref . Density distribution math rho r frac sigma V 2 2 pi G r 2 math where sub V sub sup 2 sup is the velocity dispersion and G is the gravitational constant . The SIS profile is unphysical because of the mathematical singularity singularity at zero radius and the fact that the corresponding SIS mass is Infinity infinite . However, it is commonly utilized in the literature due to the simplicity of its form. References reflist See also Navarro Frenk White profile Category Large scale structure of the cosmos ... more details
Orphan date March 2011 A primordial isocurvature baryon model , or PIB model , is a theoretical Scientific modelling model describing the development of the early universe . It may be contrasted with the a cold dark matter model, or CDM model. The PIB model was proposed in 1987 by Jim Peebles as an alternative to the CMB model which does not necessitate the existence of exotic dark matter . ref Hu 1994 06 28 ref PIB models, which ascribe all cosmic density perturbations to isocurvature modes, predict results that are inconsistent with the observational data. ref name bucher Bucher, Moodley & Turok 2000 07 24 , p. 3 ref See also Lambda CDM model Footnotes references Bibliography Cite arxiv last Bucher first Martin coauthors Kavilan Moodley, Neil Turok title Characterising the Primordial Cosmic Perturbations date 2000 07 24 eprint astro ph 0007360 Cite arxiv last Hu first Wayne title The Nature versus Nurture of Anisotropies date 1994 06 28 class astro ph arxiv astro ph 9406071 Category Physical cosmology physics stub ... more details
In mathematics, a Ringel Hall algebra is a generalization of the Hall algebra , studied by harvtxt Ringel 1990 . It has a basis of equivalence classes of objects of an abelian category, and the structure constants for this basis are related to the numbers of extensions of objects in the category. References George Lusztig , Quivers, perverse sheaves, and quantized enveloping algebras. J. Amer. Math. Soc. 4 1991 , no. 2, 365&ndash 421. Citation last1 Ringel first1 Claus Michael title Hall algebras and quantum groups doi 10.1007 BF01231516 mr 1062796 year 1990 journal Inventiones Mathematicae volume 101 issue 3 pages 583 591 cite arxiv eprint math 0611617 title Lectures on Hall algebras last Schiffmann first O year 2006 External links http www.maths.leeds.ac.uk ahubery RHAlgs.html Introduction to Ringel Hall algebras Category Representation theory Category Lie algebras Category Symmetric functions ... more details
John Lott 12 January 1959, Rolla, Missouri ref http math.berkeley.edu lott anglocv.pdf CV ref is a Professor of Mathematics at the University of California, Berkeley . He is working on Ricci flow . He and Bruce Kleiner of Yale University make up one of three teams formed for the purpose of verifying Grigori Perelman s proof of the Poincar conjecture . They posted a paper on the arXiv in May 2006 that filled in the details of Perelman s proof of the geometrization conjecture. ref cite arxiv first Bruce last Kleiner authorlink Bruce Kleiner coauthors John W. Lott title Notes on Perelman s Papers eprint math.DG 0605667 year 2006 ref References reflist External links http www.math.lsa.umich.edu lott Persondata Metadata see Wikipedia Persondata . NAME Lott, John ALTERNATIVE NAMES SHORT DESCRIPTION DATE OF BIRTH PLACE OF BIRTH DATE OF DEATH PLACE OF DEATH DEFAULTSORT Lott, John Category American mathematicians Category Living people de John Lott Mathematiker ... more details
Project X is a proposed high intensity proton accelerator complex which is to be built at the Fermi National Accelerator Laboratory . It is planned to produce beams of different energies up to 8 GeV for precision experiments involving kaons and muons . The complex can also be used to create a high intensity neutrino beam for neutrino oscillation experiments such as NO A and the Long Baseline Neutrino Experiment . Project X will be based on Superconducting Radio Frequency superconducting RF components such as those developed for the International Linear Collider . ref cite arXiv last Tschirhart first R. eprint 1109.3500 title Project X A new high intensity proton accelerator complext at Fermilab class hep ex year 2011 accessdate 2011 10 11 ref References references External links http projectx.fnal.gov Project X public website Category Fermilab Particle stub US stub ... more details
Herman Lyle Smith was an American mathematician, the co discoverer, with E. H. Moore , of net mathematics net s, ref harv Sundstr m 2010 p 15n ref and also discovered the related notion of filter mathematics filter s independently of Cartan. ref harv Sundstr m 2010 p 17n ref He received his B.S. degree from the University of Oregon in 1914 and his M.S. from the University of Chicago the following year. His Ph.D. was granted in 1926 by the University of Chicago for work done under Moore. He was later employed as a professor of mathematics by Louisiana State University . External links MathGenealogy id 6114 Notes reflist References cite arXiv last Sundstr m first Manya Raman eprint 1006.4131 title A pedagogical history of compactness class math.HO year 2010 version v1 accessdate November 18, 2010 ref harv DEFAULTSORT Smith, Herman L. Category 20th century mathematicians Category American mathematicians Category Louisiana State University faculty Category Topologists US mathematician stub ... more details
KOI 423 2MASS J19475046 4602034 is a type F7IV star located at RA 19 47 50.468 DEC 46 02 03.43 . It has Kepler space telescope Kepler Object of Interest reference number 423. One known exoplanet planet orbits it, KOI 423b . References http exoplanet.eu star.php?st KOI 423 http simbad.u strasbg.fr simbad sim id?protocol html&Ident KOI 423 cite arxiv eprint 1106.3225 author1 Bouchy author2 Bonomo author3 Santerne author4 Moutou author5 Deleuil author6 Diaz author7 Eggenberger author8 Ehrenreich author9 Gry title SOPHIE velocimetry of Kepler transit candidates III. KOI 423b An 18 Mjup transiting companion around an F7IV star class astro ph.EP year 2011 Category F type stars Category Subgiant stars exoplanet stub star stub fr KOI 423 ... more details
arxiv gr qc 0412012 bibcode 2005CQGra..22.1451L http www.arxiv.org abs gr qc 0412012 eprint version ... eprint version cite journal author Anderson, Paul R. and Brill, Dieter R. title Gravitational Geons ... arxiv gr qc 9610074 bibcode 1997PhRvD..56.4824A http www.arxiv.org abs gr qc 9610074 eprint ... more details
in question were caused by chance. ref cite arxiv eprint 1011.3706 author1 Gurzadyan VG author2 Penrose ... cite arxiv eprint 1012.1268 author1 Wehus IK author2 Eriksen HK title A search for concentric circles in the 7 year WMAP temperature sky maps class astro ph.CO date 2010 12 07 ref ref cite arxiv eprint ... variance circles on the sky class astro ph.CO date 2010 12 07 ref ref cite arxiv eprint 1012.1656 author1 ... simulation of the data. ref cite arxiv eprint 1012.1486 title More on the low variance circles ... more details
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