50,129 research outputs found
Time evolution of the Luttinger model with nonuniform temperature profile
Get PDFWe study the time evolution of a one-dimensional interacting fermion system described by the Luttinger model starting from a nonequilibrium state defined by a smooth temperature profile T (x). As a specific example we consider the case when T (x) is equal to T-L (T-R) far to the left (right). Using a series expansion in epsilon = 2(T-R -T-L)/(T-L + T-R), we compute the energy density, the heat current density, and the fermion two-point correlation function for all times t >= 0. For local (delta-function) interactions, the first two are computed to all orders, giving simple exact expressions involving the Schwarzian derivative of the integral of T (x). For nonlocal interactions, breaking scale invariance, we compute the nonequilibrium steady state (NESS) to all orders and the evolution to first order in epsilon. The heat current in the NESS is universal even when conformal invariance is broken by the interactions, and its dependence on T-L,T-R agrees with numerical results for the XXZ spin chain. Moreover, our analytical formulas predict peaks at short times in the transition region between different temperatures and show dispersion effects that, even if nonuniversal, are qualitatively similar to ones observed in numerical simulations for related models, such as spin chains and interacting lattice fermions
Steady States and Universal Conductance in a Quenched Luttinger Model
No full textWe obtain exact analytical results for the evolution of a 1+1-dimensional Luttinger model prepared in a domain wall initial state, i.e., a state with different densities on its left and right sides. Such an initial state is modeled as the ground state of a translation invariant Luttinger Hamiltonian Hλ with short range non-local interaction and different chemical potentials to the left and right of the origin. The system evolves for time t > 0 via a Hamiltonian Hλ′ which differs from Hλ by the strength of the interaction. Asymptotically in time, as t→ ∞, after taking the thermodynamic limit, the system approaches a translation invariant steady state. This final steady state carries a current I and has an effective chemical potential difference μ+- μ- between right- (+) and left- (−) moving fermions obtained from the two-point correlation function. Both I and μ+- μ- depend on λ and λ′. Only for the case λ= λ′= 0 does μ+- μ- equal the difference in the initial left and right chemical potentials. Nevertheless, the Landauer conductance for the final state, G= I/ (μ+- μ-) , has a universal value equal to the conductance quantum e2/ h for the spinless case
Author Self-Citation in the Turkish Otorhinolaryngology Literature
Get PDFObjective:To evaluate the prevalence and other characteristics of author self-citations in six Turkey-originated general otorhinolaryngology (ORL) journals of Turkish ORL literature.Methods:A total of 970 articles published in six Turkey-originated general ORL journals (ENT Updates, Journal of Ear Nose Throat and Head Neck Surgery, KBB-Forum, Praxis of Otorhinolaryngology, The Turkish Journal of Ear Nose and Throat, and Turkish Archives of Otorhinolaryngology) in 2016-2020 were analyzed for author self-citations. The association between author self-citations and journal types, study types, study topics, country of origin, and compatibility with the topic were also evaluated.Results:There were 265 author self-citations (0.273 per article) which corresponded to 1.36% of all citations. There was no significant difference between the journal types, study topics, and origin of the studies in terms of mean self-citation values per study, whereas case reports had significantly lower self-citations than review and original investigations. There were three citations (1.1%) that were irrelevant to the study topic.Conclusion:To the best of our knowledge, this is the first study that investigated the practice of author self-citation in Turkish ORL literature. Author self-citation rate in the Turkish-originated general ORL journals was found remarkably lower than the medical literature, whereas the self-citations were found compatible with the study topic to a very large extent. Members of the scientific community including authors, readers, and journal editors should be cautious regarding the unethical practices of self-citations
Inhomogeneous conformal field theory out of equilibrium
Get PDFWe study the non-equilibrium dynamics of conformal field theory (CFT) in 1+1
dimensions with a smooth position-dependent velocity explicitly breaking
translation invariance. Such inhomogeneous CFT is argued to effectively
describe 1+1-dimensional quantum many-body systems with certain inhomogeneities
varying on mesoscopic scales. Both heat and charge transport are studied,
where, for concreteness, we suppose that our CFT has a conserved U
current. Based on projective unitary representations of diffeomorphisms and
smooth maps in Minkowskian CFT, we obtain a recipe for computing the exact
non-equilibrium dynamics in inhomogeneous CFT when evolving from initial states
defined by smooth inverse-temperature and chemical-potential profiles
and . Using this recipe, the following exact analytical
results are obtained: (i) the full time evolution of densities and currents for
heat and charge transport, (ii) correlation functions for components of the
energy-momentum tensor and the U current as well as for any primary field,
and (iii) the thermal and electrical conductivities. The latter are computed by
direct dynamical considerations and alternatively using a Green-Kubo formula.
Both give the same explicit expressions for the conductivities, which reveal
how inhomogeneous dynamics opens up the possibility for diffusion as well as
implies a generalization of the Wiedemann-Franz law to finite times within CFT.Comment: 34 pages, LaTeX, 1 figure; updated and revised, final published
version; added dedication to Krzysztof Gaw\k{e}dzk
Applicativo web per audioguide - HooRMI Author
Get PDFHooRMI Author è la parte da content creator del progetto HooRMI.
La dissertazione si concentra sul funzionamento HooRMI Author, ovvero di come viene permesso all'utente di produrre contenuti video basati sulla propria posizione acquisita tramite tecnologia Plus code e caricarli sul proprio canale Youtube. I contenuti risulteranno pronti per essere selezionati e fruiti dai turisti, grazie alla profonda personalizzazione dei metadati associati ad ogni clip
Sectoral allocation by gender of Latin American workers over the liberalization period of the 1990s
Get PDFThe recent restructuring of Latin American economies has renewed interest in the effects of trade liberalization, on labor markets, and on the gender division of labor. The author does not attempt to establish casuality between economic reforms, and the types of jobs that men and women hold. Instead, she provides a detailed description of the trends in male, and female formal, and informal sector participation during the economic reform period in Argentina, Brazil, and Costa Rica. The author first compares the gender composition of the formal, informal wage, and self-employment sectors in a year before reforms (1988 for Argentina, 1989 for Brazil, and Costa Rica), and a year after reforms implementation (1997 for Argentina, 1995 for Brazil and Costa Rica). Although women continued to be more likely than men to work in the informal wage sector, there is no trend of"masculinization"or"feminization"of the informal sector, or any other. Instead, in Argentina men have overtaken women as the most prevalent workers in the informal wage sector, while in Brazil, the opposite has occurred (as men move into self-employment). In Costa Rica there have been no statistical, observable changes. The author then considers the distribution across sectors within each gender group, to identify whether men, and women are more likely to select different sectors in the post-reform period relative to the pre-reform period. Among both men, and women in all three countries (except Brazilian men), workers have become more likely to hold informal wage jobs, and less likely to hold formal sector jobs. Trends in human capital accumulation explain these changes for both men, and women, while changes in gender roles, primarily in homecare and marriage, do not seem to have an effect.Health Monitoring&Evaluation,Labor Policies,Population&Development,Public Health Promotion,Environmental Economics&Policies,Health Monitoring&Evaluation,Environmental Economics&Policies,Population&Development,Banks&Banking Reform,Work&Working Conditions
Number of 3-grams per author (in thousands).
No full textNumber of 3-grams per author (in thousands).</p
Production, productivity per author and per age group of authors of new Siluriformes species descriptions.
No full text<p>Production, black columns, y1 axis; Productivity per author, grey columns, y2 axis; Productivity per age group, striped columns, y2 axis.</p
The dynamics of unreliable narration:Implicit and omitted authors, double narratees and constructive readers in first person unreliable narration
No full textPer Krogh Hansen brings attention to one of the most discussed narratological concepts in recent years, the ‘unreliable narrator’. In the article »The Dynamics of Unreliable Narration«, Hansen is considering to what extent the question of authorial control or intention is relevant when analysing and interpreting unreliable narrators. In the first part of the article, he questions this claimed essentiality of an authorial agent from three different angles: One concerning the border between diegetic and extradiegetic issues. Another with specific focus on unreliable simultaneous narration (first person, present tense). And a third with attention paid to the role of unreliable narrators in factual narratives. In the article, he proposes a model for describing the different dynamic roles the authorial agent, as well as the empirical reader, plays in different forms of unreliable narration. Here, terms like ‘implicit author’, ‘omitted author’, ‘double narratees’ and ‘constructive readers’ are introduced andillustrated by examples of Dennis Cooper and Edgar Allan Poe
Average per-author h-index vs Average REF Impact Score.
No full textAverage per-author h-index vs Average REF Impact Score.</p
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