161 research outputs found
Photo-induced gap closure in an excitonic insulator
We study the dynamical phase transition out of an excitonic insulator phase
after photo-excitation using a time-dependent extension of the selfconsistent
GW method. We connect the evolution of the photoemission spectra to the
dynamics of the excitonic order parameter and identify two dynamical phase
transition points marked by a slowdown in the relaxation: one critical point is
connected with the trapping in a nonthermal state with reduced exciton density
and the second corresponds to the thermal phase transition. The transfer of
kinetic energy from the photoexcited carriers to the exciton condensate is
shown to be the main mechanism for the gap melting. We analyze the low energy
dynamics of screening, which strongly depends on the presence of the excitonic
gap, and argue that it is difficult to interpret the static component of the
screened interaction as the effective interaction of some low energy model.
Instead we propose a phenomenological measure for the effective interaction
which indicates that screening has minor effects on the low energy dynamics
Toward Calculus via Real-time Measurements
Several years of my experiences in the use of real-time experiments are now upgraded in order to enhance also the teaching of mathematics. The motion sensor device enables us to get real time x(t) and v(t) graphs of a moving object or person. We can productively use these graphs to introduce differentiation on visual level as well as to show the integration procedure. The students are fully involved in the teaching as they are invited to walk in front of the sensor. This approach motivates them by the realistic aspects of mathematical structures. The method could help to fulfill the credo of teaching: comprehension before computation. The steps of such an approach are explained and discussed in further detail below
“Zoopoetic Dwelling”: The Ecology of the Connectedness of Animal and Human Homes and Dwelling Through Folklore and Literary Representations
The act of dwelling and physical dwellings is not an exclusively human domain: all spaces, environments and homes of various animals are included. The question of whether an animal merely exists or also lives and dwells forms the basis of the article. We examine the types of environment in which nonhuman animals live either together with people or independently and those where they build their dwellings. We look at the difference between dwelling and building. We will present three viewpoint models that consider animals, their dwelling and physical dwellings on the basis of folkloristic, anthropological, philosophical, eco-critical, and critical-animalistic findings. They are the anthropocentric, anthropomorphic, and zoo-centric models as they appear in the works of Fran Erjavec (Domače in tuje živali v podobah, 1868-1873), Richard Adams (Watership Down, 1972) and Iztok Geister (Narava, kot jo vidi narava, 2010). The way these works present animals and their dwellings, more or less closely reflecting reality, will aid in determining whether these dwellings are part of nature or culture. We will be asking, for example, whether the beaver’s dwelling is an architectural masterpiece or merely a result of instinctive behaviour. Our starting point is based on the understanding that animals are persons and, as such, are capable of dwelling and intentionally producing their physical dwellings
Low rank compression in the numerical solution of the nonequilibrium Dyson equation
We propose a method to improve the computational and memory efficiency of
numerical solvers for the nonequilibrium Dyson equation in the Keldysh
formalism. It is based on the empirical observation that the nonequilibrium
Green's functions and self energies arising in many problems of physical
interest, discretized as matrices, have low rank off-diagonal blocks, and can
therefore be compressed using a hierarchical low rank data structure. We
describe an efficient algorithm to build this compressed representation on the
fly during the course of time stepping, and use the representation to reduce
the cost of computing history integrals, which is the main computational
bottleneck. For systems with the hierarchical low rank property, our method
reduces the computational complexity of solving the nonequilibrium Dyson
equation from cubic to near quadratic, and the memory complexity from quadratic
to near linear. We demonstrate the full solver for the Falicov-Kimball model
exposed to a rapid ramp and Floquet driving of system parameters, and are able
to increase feasible propagation times substantially. We present examples with
262144 time steps, which would require approximately five months of computing
time and 2.2 TB of memory using the direct time stepping method, but can be
completed in just over a day on a laptop with less than 4 GB of memory using
our method. We also confirm the hierarchical low rank property for the driven
Hubbard model in the weak coupling regime within the GW approximation, and in
the strong coupling regime within dynamical mean-field theory.Comment: 14 page
A Multi-species World in the Poetry of Alenka Jovanovski and Vesna Liponik
The article examines selected poems that deal with the inter-species relations in a multi-species world, from the collections of poems Tisoč osemdeset stopinj (Thousand Eighty Degrees) by Alenka Jovanovski and roko razje (Eats Away the Hand) byVesna Liponik. Through the analysis and interpretation, we investigate how their poetics work when it collides with the demonization of the other and the overt or covert social and environmental speciesism. In doing so, we discuss the symbolic and active power of poetry, the poets’ critique of the binary divide between man and other beings, and their emphasis on the inherent value of animal and, in awider context, their political-economic critique of global capitalism and linguistic, symbolic, material human violence against other species and nature
Rošlin in Verjanko. Transformacija ljudske balade v sodobna prozna besedila
Razprava raziskuje postmodernistični poskus prenosa slovenske ljudske družinske balade Rošlin in Verjanko v sodobno slovensko prozo. Po analizi ljudskih variant balade, osvetlitvi antičnega mita, Prešernove predelave in Kersnikove obdelave motiva se avtorica osredotoča na zbirko sodobnih kratkih zgodb z naslovom Rošlin in Verjanko ali Dolgo odlagani opravek slovenstva iz leta 1987, kjer ugotavlja okvare in transformacije balade in predstavlja različne avtorske interpretativne poskuse od Andreja Blatnika do Igorja Zabela ter poznejšo samostojno obdelavo snovi Marka Golje.
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The paper examines a postmodernist transmission of Slovenian family ballad Rošlin in Verjanko (Rošlin and Verjanko) into modern Slovenian prose. After the initial analysis of variants of this folk ballad, an antique myth with a similar theme, and Prešeren’s and Kersnik’s reworking of the motif the author focuses on a collection of modern short stories titled Rošlin in Verjanko, ali Dolgo odlagani opravek slovenstva (Rošlin and Verjanko, or the Long- Postponed Slovenian Errand, 1987). Discussed are transformations and interpretations of the ballad as seen through the eyes of fourteen authors
Ljudsko pesemsko izročilo kot kulturni spomin Jančarjevega romana in drame Katarina, pav in jezuit
Na podlagi teoretskih premis o kulturnem, kolektivnem, zgodovinskem in individualnem spominu je v razpravi opredeljeno ljudsko pesemsko izročilo kot eden izmed t. i. nacionalnih kulturnih kanonov za različna literarna dela na Slovenskem. Razprava ob zgodovinskih in kulturnih prvinah (barok, romanje v Porenje, sedemletna vojna, ljudsko prozno izročilo, ljudska verovanja, ljudsko gledališče, materialna kultura) v Jančarjevem romanu in drami Katarina, pav in jezuit [2000 in 2005] odkriva medbesedilne vloge ljudske pesmi kot ene izmed temeljnih duhovnih podlag romana in drame, ki so vpisane v obe deli kot del zgodovinskega in kulturnega kolektivnega spomina, a tudi kot del individualnega avditivnega in vizualnega spomina slovenskega avtorja. Ljudsko pesem je pisatelj vpisal v oba žanra v sinkretični celoti: tekst, tekstura, ob upoštevanju nosilca in fenomena romanja kot družbenega konteksta pesmi, zato so v razpravi predstavljena polisemantična polja vsebinsko raznovrstne ljudske pesemske dediščine, predvsem romarskih pesmi, s posebno analizo ljudske pripovedne legendarne pesmi Marija in brodnik.
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Based on theoretical premises about cultural, collective, historic, and individual memory Slovenian folk song heritage has been defined as one of the so-called cultural canons of literary works. Analyzing historic and cultural elements (baroque, pilgrimage to Rhineland, Seven Years’ War, folk narrative tradition, folk beliefs, folk theater, and material culture) in Drago Jančar’s novel Katarina, pav in jezuit (Kahtarina, the Peacock, and the Jesuit; published in 2000 and adapted for stage in 2005), this study examines intertextual roles of folk song, which serves as a primary spiritual foundation for the novel and the play. In both texts, these intertextual roles figure as part of historic and cultural collective memory on one hand and as part of Jančar’s individual auditory and visual memory on the other. In both the novel and the drama, folk song has been intertwined with Jančar’s own text in its syncretic entirety, which takes into consideration not only the text and texture but also the phenomenon of pilgrimage and its participants within the social context of folk song. In view of the above, this study presents polysemantic fields of different kinds of folk song heritage, especially pilgrimage songs, along with an analysis of folk narrative legendary song Marija in brodnik (Mary and the Ferryman)
Zoofolkloristika: Prvi uvidi na putu prema novoj disciplini
The author notes that new, more complex researches of connections between animals, nature and connections to humans are needed in Slovenian and European folklore, literature and cultural studies, due to new ecological and ethical findings in the wider social and cultural environment and a changing order of the world, which has moved the focus from anthropocentrism into ecocentrism. The discussion builds upon various theoretical discourses, new concepts and multidisciplinary knowledge, to create the foundations, guidelines and directions for a new academic discipline of zoofolkloristics. Furthermore, new theoretical and analytical discourses should enable zoofolkloristics to provide an insight into changes in human attitudes to animals, in both folklore and within traditional and contemporary ritual practices, or their redefinition, and at the same time exert influence upon legal safety of non-human subjectivities.Autorica polazi od tvrdnje da su potrebna nova, kompleksnija istraživanja veza između životinja, prirode i poveznica s ljudima u slovenskoj i europskoj folkloristici, znanosti o književnosti i kulturnim studijima, zbog novih ekoloških i etičkih uvida u širu društveno-kulturnu okolinu i promjene u svijetu, koje su dovele do promjene od antropocentrizma k ekocentrizmu. U radu se na temelju različitih teorijskih diskursa, novih pojmova i multidisciplinarnog znanja stvaraju temelji, smjernice i pravci istraživanja u novoj znanstvenoj disciplini zoofolkloristike. Autorica tvrdi da bi etnologija, folkloristika i znanost o književnosti mogle imati ključnu ulogu u razvoju ekološke svijesti, znanstvenih terenskih istraživanja i kulturne ekologije te tako omogućiti prelazak iz ekologije u eshatologiju. Rad započinje opisom percepcije životinja i odnosa ljudi i životinja, gdje autorica govori o temeljnim pojmovima koji utječu na uvođenje ove nove znanstvene discipline, kao što su: životinja kao ispitanik, individualni pristup životinji, sinantropski i antropofilni pogled na čovjeka i životinju te antropomorfizam. Zatim se govori o povijesnim i suvremenim filozofsko-antropološkim diskursima o ljudskom pogledu na životinju te o teoriji specizma. Autorica razmatra predmet nove discipline te kaže da je u centru istraživanja životinja u folkloru u najširem mogućem smislu, u svim sferama narodne kulture, što se proučava iz novih gledišta, nove percepcije i recepcije; u pjesmama, pričama, bajkama, basnama, predajama, poslovicama, izrekama, zagonetkama, šalama, narodnom jeziku, kulturnim praksama, narodnom teatru, mitologiji, narodnoj medicini pa čak i u narodnoj glazbi. Nadalje, autorica daje pregled kulturnih istraživanja životinja u Europi i Sloveniji, te pokazuje da su rasprave o životinjama uglavnom objavljivane u 21. stoljeću, što bi moglo označavati da je riječ o prelasku u novu paradigmu ili čak i novu ontologiju. Autorica se bavi metodološkim i teorijskim pitanjima i pravcima u zoofolklorističkim istraživanjima koje klasificira prema kritičkom diskursu. Rad završava pregledom ciljeva zoofolkloristike, za koju tvrdi da ne bi smjela postati znanstvena disciplina koja nema aktivan utjecaj na društvenopolitički prostor u kojem koegzistiraju ljudski i ne-ljudski subjektiviteti
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