9,823 research outputs found
Inhomogeneous quenches in the transverse field Ising chain: scaling and front dynamics
We investigate the non-equilibrium dynamics of the transverse field quantum
Ising chain evolving from an inhomogeneous initial state given by joining two
macroscopically different semi-infinite chains. We obtain integral expressions
for all two-point correlation functions of the Jordan-Wigner Majorana fermions
at any time and for any value of the transverse field. Using this result, we
compute analytically the profiles of various physical observables in the
space-time scaling limit and show that they can be obtained from a hydrodynamic
picture based on ballistically propagating quasiparticles. Going beyond the
hydrodynamic limit, we analyze the approach to the non-equilibrium steady state
and find that the leading late time corrections display a lattice effect. We
also study the fine structure of the propagating fronts which are found to be
described by the Airy kernel and its derivatives. Near the front we observe the
phenomenon of energy back-flow where the energy locally flows from the colder
to the hotter region
On some covering problems in geometry
We present a method to obtain upper bounds on covering numbers. As
applications of this method, we reprove and generalize results of Rogers on
economically covering Euclidean -space with translates of a convex body, or
more generally, any measurable set. We obtain a bound for the density of
covering the -sphere by rotated copies of a spherically convex set (or, any
measurable set). Using the same method, we sharpen an estimate by
Artstein--Avidan and Slomka on covering a bounded set by translates of another.
The main novelty of our method is that it is not probabilistic. The key idea,
which makes our proofs rather simple and uniform through different settings, is
an algorithmic result of Lov\'asz and Stein.Comment: 9 pages. IMPORTANT CHANGE: In previous versions of the paper, the
illumination problem was also considered, and I presented a construction of a
body close to the Euclidean ball with high illumination number. Now, I
removed this part from this manuscript and made it a separate paper, 'A Spiky
Ball'. It can be found at http://arxiv.org/abs/1510.0078
Marine science from cartographic viewpoint: from research to education in Hungary | Tengertan térképészet szemmel: a kutatåstól az oktatåsig Magyarorszågon
KĂ©t Ă©s fĂ©l Ă©vtizedes magyar kutatĂĄsok, valamint a tĂ©mĂĄhoz kapcsolĂłdĂł kĂŒlföldi szakirodalom magyar adaptĂĄciĂłja Ă©s szintĂ©zise eredmĂ©nyekĂ©ppen, ma mĂĄr korszerƱ Ă©s elegendĆ tudĂĄssal rendelkezĂŒnk ahhoz, hogy a tengerfenĂ©knek a szĂĄrazföldek leĂrĂłföldrajzĂĄhoz hasonlĂł rĂ©szletessĂ©gƱ leĂrĂĄsĂĄt adjuk. Ez adta az ötletet, hogy kurzust szervezzĂŒnk
a Miskolci Ă©s a Szegedi Egyetemen âTengertan I. â MorfolĂłgiaâ, illetve âTengertan tĂ©rkĂ©pĂ©sz szemmelâ cĂmmel.
Jelen tanulmĂĄnyban összegzem kutatĂĄsaim törtĂ©netĂ©t, hĂĄlĂĄs tisztelettel Klinghammer IstvĂĄn professzor Ășrnak.
A tudomĂĄnyos munkĂĄssĂĄgomhoz kapcsolĂłdĂł sikerek kĂ©t idĆszakra Ă©s kĂ©t kĂŒlönbözĆ hasznosĂtĂĄsi terĂŒletre oszthatĂłk.
Az elsĆ idĆszakban (1974â90) az eredmĂ©nyek gyakorlati hasznosulĂĄsa jellemzĆ, nem vĂ©letlenĂŒl, hiszen ekkor a KartogrĂĄfiai VĂĄllalat munkatĂĄrsa voltam. MĂg a mĂĄsodik â nagyjĂĄbĂłl az 1990-es Ă©vek elejĂ©n elkezdĆdött â idĆszakban az ELTE oktatĂłjakĂ©nt a kutatĂĄs ĂĄttevĆdött az egyetemre, hallgatĂłk bevonĂĄsĂĄval folyt, de az ezredfordulĂł elejĂ©ig âcsakâ nemzetközi visszhangot is kivĂĄltĂł elmĂ©leti eredmĂ©nyek szĂŒlettek, az eredmĂ©nyek ugyan folyamatosan beĂ©pĂŒltek az oktatĂĄsba, azonban âlĂĄtvĂĄnyosabb hasznosĂtĂĄsukâ kĂŒlönbözĆ kiadvĂĄnyokban csak 2003 Ă©s 2004 folyamĂĄn valĂłsulhatott meg.
SzĂŒksĂ©gesnek lĂĄtom azonban a fizikai oceanogrĂĄfia eredmĂ©nyeinek tĂ©rkĂ©pi szintĂ©zisĂ©t, összegzĂ©sĂ©t Ă©s
âhonosĂtĂĄsĂĄtâ is. A 2004-ben a TopogrĂĄfâNyĂr-Karta kiadta âNagy VilĂĄgatlaszbaâ elkĂ©szĂtettem a 32 oldalas
TENGERFENĂK-DOMBORZAT cĂmƱ fejezetet. A kiadĂłval tovĂĄbbi 40 oldalnyi tematikus tĂ©rkĂ©ppel kibĆvĂtett kiadĂĄsrĂłl
tĂĄrgyalunk, a felsĆoktatĂĄs Ă©s a doktorkĂ©pzĂ©s szĂĄmĂĄra.
After having pursued research of marine science for two and half decades, and after having synthesized international literature on this discipline and adapted it to the Hungarian language, we are in possession of a level of modern knowledge sufficient to give a detailed and adequate description of the seafloor, similar to descriptive geography of continents. This gave us the idea to organize a course at the University of Miskolc and Szeged as well with the titles âMarine Science I â Morphologyâand âMarine Science from Cartographic Viewpointâ. This paper gives a summary of the history of this research, with grateful respects to Professor IstvĂĄn Klinghammer.
My achievements in research can be divided in two periods fundamentally different in practical respect. In the first period (1974â90), when I was working for the KartogrĂĄfiai VĂĄllalat, my results were typically utilized in practice. During the second period, which began in the early 1990s, being a lecturer at Eötvös LorĂĄnd University, I transferred my research to the university, where several students joined the project. Until the first years of the new millennium, we could âonlyâ achieve theoretical results; although these results elicited international reaction and were incorporated in education, they could be utilized in various publications âspectacularlyâ only during 2003 and 2004.
I also find the cartographical synthesis, summary and ânationalizationâ of results of physical oceanography
important. I prepared a chapter of 32 pages with the title âSeafloor Reliefâ, which was published in 2004 by
TopogrĂĄfâNyĂr-Karta in their âGreat World Atlasâ. We are negotiating with the publishing company about a more comprehensive publication including 40 new pages of thematic maps for the university and postgraduate training
On the Schneider-Vigneras functor for principal series
We study the Schneider-Vigneras functor attaching a module over the Iwasawa
algebra to a -representation for irreducible modulo
principal series of the group for any finite field extension
.Comment: After major revision, 21 pages, to appear in Journal of Number Theor
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