scholarly journals Phase transitions from the fifth dimension

2021 ◽  
Vol 2021 (2) ◽  
Author(s):  
Kaustubh Agashe ◽  
Peizhi Du ◽  
Majid Ekhterachian ◽  
Soubhik Kumar ◽  
Raman Sundrum
Keyword(s):  
Bubble Dynamics ◽  
Effective Field ◽  
Bubble Nucleation ◽  
Thin Wall ◽  
Black Brane ◽  
Composite Higgs ◽  
Fifth Dimension ◽  
Two Phases ◽  
Holographic Description ◽  
The Impact

Abstract We study the cosmological transition of 5D warped compactifications, from the high-temperature black-brane phase to the low-temperature Randall-Sundrum I phase. The transition proceeds via percolation of bubbles of IR-brane nucleating from the black-brane horizon. The violent bubble dynamics can be a powerful source of observable stochastic gravitational waves. While bubble nucleation is non-perturbative in 5D gravity, it is amenable to semiclassical treatment in terms of a “bounce” configuration interpolating between the two phases. We demonstrate how such a bounce configuration can be smooth enough to maintain 5D effective field theory control, and how a simple ansatz for it places a rigorous lower-bound on the transition rate in the thin-wall regime, and gives plausible estimates more generally. When applied to the Hierarchy Problem, the minimal Goldberger-Wise stabilization of the warped throat leads to a slow transition with significant supercooling. We demonstrate that a simple generalization of the Goldberger-Wise potential modifies the IR-brane dynamics so that the transition completes more promptly. Supercooling determines the dilution of any (dark) matter abundances generated before the transition, potentially at odds with data, while the prompter transition resolves such tensions. We discuss the impact of the different possibilities on the strength of the gravitational wave signals. Via AdS/CFT duality the warped transition gives a theoretically tractable holographic description of the 4D Composite Higgs (de)confinement transition. Our generalization of the Goldberger-Wise mechanism is dual to, and concretely models, our earlier proposal in which the composite dynamics is governed by separate UV and IR RG fixed points. The smooth 5D bounce configuration we introduce complements the 4D dilaton/radion dominance derivation presented in our earlier work.

scholarly journals The present and future of four top operators

2021 ◽  
Vol 2021 (2) ◽  
Author(s):  
Giovanni Banelli ◽  
Ennio Salvioni ◽  
Javi Serra ◽  
Tobias Theil ◽  
Andreas Weiler
Keyword(s):  
Top Quark ◽  
High Energy ◽  
New Physics ◽  
Effective Field ◽  
Proton Proton ◽  
Strongly Coupled ◽  
Composite Higgs ◽  
Electron Positron ◽  
Energy Frontier ◽  
The Impact

Abstract We study the phenomenology of a strongly-interacting top quark at future hadron and lepton colliders, showing that the characteristic four-top contact operators give rise to the most significant effects. We demonstrate the extraordinary potential of a 100 TeV proton-proton collider to directly test such non-standard interactions in four-top production, a process that we thoroughly analyze in the same-sign dilepton and trilepton channels, and explore in the fully hadronic channel. Furthermore, high-energy electron-positron colliders, such as CLIC or the ILC, are shown to exhibit an indirect yet remarkable sensitivity to four-top operators, since these constitute, via renormalization group evolution, the leading new-physics deformations in top-quark pair production. We investigate the impact of our results on the parameter space of composite Higgs models with a strongly-coupled (right-handed) top quark, finding that four-top probes provide the best sensitivity on the compositeness scale at the future energy frontier. In addition, we investigate mild yet persisting LHC excesses in multilepton plus jets final states, showing that they can be consistently described in the effective field theory of such a new-physics scenario.

Awareness-Raising in the TEFL Phonology Classroom

2004 ◽  
Vol 145-146 ◽  
pp. 219-268 ◽  
Author(s):  
Lawrence Zhang
Keyword(s):  
Native Speaker ◽  
Psychological Needs ◽  
British English ◽  
Linguistic Imperialism ◽  
Teacher Student ◽  
Suprasegmental Features ◽  
Discourse Intonation ◽  
Awareness Raising ◽  
Two Phases ◽  
The Impact

This paper reports on two phases of a study of a group of advanced TEFL (teachers-of-English-as-a-foreign-language) students. To raise their awareness of the importance of discourse intonation while they were receiving teacher training, this study focuses on examining their sociocultural and psychological inclinations in the choice of phonological models. The first phase is an exploration of their attitudes toward, a native-speaker variety (British English) and a nonnative (Chinese EFL-speaker) variety of English pronunciation and intonation. The second reports on a didactic intervention study of the impact of activities that engaged the students in the awareness-raising of the importance of suprasegmental features, especially discourse intonation, on self-perceptions of their efficacy and confidence in communication. The results showed a systematic pattern of participant endorsement for a native-speaker model and a clear improvement in theIr perceptions of the importance of suprasegmental features of standard English because of teacher-student co-construction of meaning through interactive awareness-raising activities. The findings are discussed with reference to the students' sociocultural and psychological needs in TEFL training, particularly with reference to recent academic discourse on the issue of “linguistic imperialism” (Canagarajah, 1999; Phillipson, 1992, 1996) and ElL in pedagogy (Jenkins, 1998, 2002) and their wider implications in typical EFL contexts.

Kazimir Malevich: Economy as the Fifth Dimension

2019 ◽  
Vol 29 (6) ◽  
pp. 215-228
Keyword(s):  
Karl Marx ◽  
Dialectical Materialism ◽  
Economic Base ◽  
Surplus Value ◽  
Bourgeois Society ◽  
Fifth Dimension ◽  
Fourth Volume ◽  
Contemporary Painting ◽  
New Criterion ◽  
The Impact

This paper deals with the impact that Karl Marx"s Das Kapital (and especially its fourth volume, the theory of Surplus Value) had on the category of economy in Kazimir Malevich"s output. In a series of texts, Malevich proclaims economy the new criterion of art and the Black Square its embodiment in contemporary painting. While the author was analyzing Marx"s views on labor and human nature, echoes of them turned up in Malevich"s manifestos and philosophical essays where the artist pondered the idea of the liberation of creative exaltation. The article others an interpretation of the creative process itself from the standpoint of economy, which for Malevich provided an opportunity to lay down the foundation for a new kind of art that was consistent with the prevailing ideology. The author points out that while Malevich was in Vitebsk he studied Marx"s works with idea of incorporating economic studies into art: his speculations on the relationships between the ideological superstructure and the practical, economic base were written in the manner of Marxist philosophy and provided the basis for his main essays, The World as Non-Objectivity (1923) and Suprematism: Thee World as Non-Objectivity or Eternal Rest (1923-1924). They defined the new art as an independent ideological superstructure positioned “outside of other contents and ideologies.” Parallel to that, the author examines the correspondence between Malevich"s theory of the surplus element and Marxist doctrines on surplus value. It is also shown that Malevich hoped to prove that, as in dialectical materialism, his new surplus element opens the way to a new artistic structure that is emerging from the womb of the old system in the same way that communism comes about as a kind of heterogeneous body from within the underpinnings of bourgeois society.

scholarly journals Theoretical uncertainties for cosmological first-order phase transitions

2021 ◽  
Vol 2021 (4) ◽  
Author(s):  
Djuna Croon ◽  
Oliver Gould ◽  
Philipp Schicho ◽  
Tuomas V. I. Tenkanen ◽  
Graham White
Keyword(s):  
Phase Transitions ◽  
Standard Model ◽  
Scale Dependence ◽  
Effective Field ◽  
Bubble Nucleation ◽  
Perturbative Approach ◽  
First Order ◽  
The Standard Model ◽  
First Order Phase ◽  
Renormalisation Scale

Abstract We critically examine the magnitude of theoretical uncertainties in perturbative calculations of fist-order phase transitions, using the Standard Model effective field theory as our guide. In the usual daisy-resummed approach, we find large uncertainties due to renormalisation scale dependence, which amount to two to three orders-of-magnitude uncertainty in the peak gravitational wave amplitude, relevant to experiments such as LISA. Alternatively, utilising dimensional reduction in a more sophisticated perturbative approach drastically reduces this scale dependence, pushing it to higher orders. Further, this approach resolves other thorny problems with daisy resummation: it is gauge invariant which is explicitly demonstrated for the Standard Model, and avoids an uncontrolled derivative expansion in the bubble nucleation rate.

scholarly journals Top-induced contributions to H → $$ b\overline{b} $$ and H → $$ c\overline{c} $$ at $$ \mathcal{O}\left({\alpha}_s^3\right) $$

2020 ◽  
Vol 2020 (12) ◽  
Author(s):  
Roberto Mondini ◽  
Ulrich Schubert ◽  
Ciaran Williams
Keyword(s):  
Top Quark ◽  
Clustering Algorithm ◽  
Percent Level ◽  
Effective Field ◽  
Total Width ◽  
Monte Carlo Code ◽  
Final State ◽  
Fully Differential ◽  
State Selection ◽  
The Impact

Abstract In this paper we present a fully-differential calculation for the contributions to the partial widths H →$$ b\overline{b} $$ b b ¯ and H →$$ c\overline{c} $$ c c ¯ that are sensitive to the top quark Yukawa coupling yt to order $$ {\alpha}_s^3 $$ α s 3 . These contributions first enter at order $$ {\alpha}_s^2 $$ α s 2 through terms proportional to ytyq (q = b, c). At order $$ {\alpha}_s^3 $$ α s 3 corrections to the mixed terms are present as well as a new contribution proportional to $$ {y}_t^2 $$ y t 2 . Our results retain the mass of the final-state quarks throughout, while the top quark is integrated out resulting in an effective field theory (EFT). Our results are implemented into a Monte Carlo code allowing for the application of arbitrary final-state selection cuts. As an example we present differential distributions for observables in the Higgs boson rest frame using the Durham jet clustering algorithm. We find that the total impact of the top-induced (i.e. EFT) pieces is sensitive to the nature of the final-state cuts, particularly b-tagging and c-tagging requirements. For bottom quarks, the EFT pieces contribute to the total width (and differential distributions) at around the percent level. The impact is much bigger for the H →$$ c\overline{c} $$ c c ¯ channel, with effects as large as 15%. We show however that their impact can be significantly reduced by the application of jet-tagging selection cuts.

Integrated Production Model as a Tool for Optimization the Development Strategy of the Sakhalin Oil and Gas Condensate Field

2021 ◽  
Author(s):  
Oleksandr Doroshenko ◽  
Miljenko Cimic ◽  
Nicholas Singh ◽  
Yevhen Machuzhak
Keyword(s):  
History Matching ◽  
Effective Field ◽  
Production Optimization ◽  
Production Model ◽  
Production Forecast ◽  
Hydrocarbon Production ◽  
Integrated Production ◽  
Wellhead Pressure ◽  
Field Development ◽  
The Impact

Abstract A fully integrated production model (IPM) has been implemented in the Sakhalin field to optimize hydrocarbons production and carried out effective field development. To achieve our goal in optimizing production, a strategy has been accurately executed to align the surface facilities upgrade with the production forecast. The main challenges to achieving the goal, that we have faced were:All facilities were designed for early production stage in late 1980's, and as the asset outdated the pipeline sizes, routing and compression strategies needs review.Detecting, predicting and reducing liquid loading is required so that the operator can proactively control the hydrocarbon production process.No integrated asset model exists to date. The most significant engineering tasks were solved by creating models of reservoirs, wells and surface network facility, and after history matching and connecting all the elements of the model into a single environment, it has been used for the different production forecast scenarios, taking into account the impact of infrastructure bottlenecks on production of each well. This paper describes in detail methodology applied to calculate optimal well control, wellhead pressure, pressure at the inlet of the booster compressor, as well as for improving surface flowlines capacity. Using the model, we determined the compressor capacity required for the next more than ten years and assessed the impact of pipeline upgrades on oil gas and condensate production. Using optimization algorithms, a realistic scenario was set and used as a basis for maximizing hydrocarbon production. Integrated production model (IPM) and production optimization provided to us several development scenarios to achieve target production at the lowest cost by eliminating infrastructure constraints.

scholarly journals Deciphering The Molecular Mechanism Of Water Boiling At Heterogeneous Interfaces

2021 ◽  
Author(s):  
Konstantinos Karalis ◽  
Dirk Zahn ◽  
Nikolaos Prasianakis ◽  
Bojan Niceno ◽  
Sergey V. Churakov
Keyword(s):  
Molecular Mechanism ◽  
Heat Removal ◽  
Nucleate Boiling ◽  
Surface Hydrophobicity ◽  
Bubble Nucleation ◽  
Geothermal Systems ◽  
Transition Path ◽  
Nucleation Sites ◽  
Dynamics Simulations ◽  
The Impact

Abstract Water boiling control evolution of natural geothermal systems is widely exploited in industrial processes due to the unique non-linear thermophysical behavior. Even though the properties of water both in the liquid and gas state have been extensively studied experimentally and by numerical simulations, there is still a fundamental knowledge gap in understanding the mechanism of the heterogeneous nucleate boiling controlling evaporation and condensation. In this study, the molecular mechanism of bubble nucleation at the hydrophilic and hydrophobic solid-water interface was determined by performing unbiased molecular dynamics simulations using the transition path sampling scheme. Analyzing the liquid to vapor transition path, the initiation of small void cavities (vapor bubbles nuclei) and their subsequent merging mechanism, leading to successively growing vacuum domains (vapor phase), has been elucidated. The molecular mechanism and the boiling nucleation sites' location are strongly dependent on the solid surface hydrophobicity and hydrophilicity. Then simulations reveal the impact of the surface functionality on the adsorbed thin water molecules film structuring and the location of high probability nucleation sites. Our findings provide molecular-scale insights into the computational aided design of new novel materials for more efficient heat removal and rationalizing the damage mechanisms.

scholarly journals Deciphering the molecular mechanism of water boiling at heterogeneous interfaces

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Konstantinos Karalis ◽  
Dirk Zahn ◽  
Nikolaos I. Prasianakis ◽  
Bojan Niceno ◽  
Sergey V. Churakov
Keyword(s):  
Molecular Mechanism ◽  
Heat Removal ◽  
Nucleate Boiling ◽  
Surface Hydrophobicity ◽  
Bubble Nucleation ◽  
Geothermal Systems ◽  
Transition Path ◽  
Nucleation Sites ◽  
Dynamics Simulations ◽  
The Impact

AbstractWater boiling control evolution of natural geothermal systems is widely exploited in industrial processes due to the unique non-linear thermophysical behavior. Even though the properties of water both in the liquid and gas state have been extensively studied experimentally and by numerical simulations, there is still a fundamental knowledge gap in understanding the mechanism of the heterogeneous nucleate boiling controlling evaporation and condensation. In this study, the molecular mechanism of bubble nucleation at the hydrophilic and hydrophobic solid–water interface was determined by performing unbiased molecular dynamics simulations using the transition path sampling scheme. Analyzing the liquid to vapor transition path, the initiation of small void cavities (vapor bubbles nuclei) and their subsequent merging mechanism, leading to successively growing vacuum domains (vapor phase), has been elucidated. The molecular mechanism and the boiling nucleation sites’ location are strongly dependent on the solid surface hydrophobicity and hydrophilicity. Then simulations reveal the impact of the surface functionality on the adsorbed thin water molecules film structuring and the location of high probability nucleation sites. Our findings provide molecular-scale insights into the computational aided design of new novel materials for more efficient heat removal and rationalizing the damage mechanisms.

scholarly journals Surging virtual reference services: COVID-19 a game changer

2021 ◽  
Vol 82 (3) ◽  
pp. 106
Author(s):  
Marie L. Radford ◽  
Laura Costello ◽  
Kaitlin Montague
Keyword(s):  
Academic Library ◽  
The United States ◽  
User Interactions ◽  
Virtual Reference ◽  
Longitudinal Surveys ◽  
Reference Services ◽  
Key Points ◽  
Academic Librarian ◽  
Two Phases ◽  
The Impact

In March 2020, academic libraries across the United States closed and sent everyone home, some destined to not reopen for months. University offices closed. Classes were moved online. Suddenly, librarians and staff pivoted to working from home and to all remote services, without time for planning logistics or training. To study the impact of this extraordinary and sweeping transition on virtual reference services (VRS), we conducted a major study of academic library responses to the pandemic that focused on librarian perceptions of how services and relationships with users morphed during this COVID-19 year.Academic librarians rallied to our call, and we collected a total of 300 responses to two longitudinal surveys launched at key points during the pandemic. Data collection focused on two phases in 2020: 1) shutdown and immediate aftermath (mid-March to July), and 2) fall ramp up and into the semester (August to December). Via Zoom, we also interviewed 28 academic librarian leaders (e.g., heads of reference and/or VRS, associate directors for User Services) from September to November. Surveys and interviews centered on adaptations and innovations to reference services, especially VRS and perceptions of changes in user interactions.

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