912 research outputs found
The diagonal and off-diagonal quark number susceptibility of high temperature and finite density QCD
We study the quark number susceptibility of the hot quark-gluon plasma at
zero and non-zero quark number density, using lattice Monte Carlo simulations
of an effective theory of QCD, electrostatic QCD (EQCD). Analytic continuation
is used to obtain results at non-zero quark chemical potential. We measure both
flavor singlet (diagonal) and non-singlet (off-diagonal) quark number
susceptibilities. The diagonal susceptibility approaches the perturbative
result above 20T_c, but below that temperature we observe significant
deviations. The results agree well with 4d lattice data down to temperatures
2T_c. The off-diagonal susceptibility is more prone to statistical and
systematic errors, but the results are consistent with perturbation theory
already at 10T_c.Comment: 21 pages, 8 figures. Published version, references added, conclusions
unchange
The argumentation in Galatians
Many exegetes set out to analyse not only rhetorical features in Galatians but also other features relating to Paul’s argumentation. Still, the use of insights from modern argumentation theory has been modest and no full-fledged argumentation analyses of Paul’s argumentation have yet been attempted. However, modern methods for argumentation analysis provide useful tools for such an undertaking. Using the pragmadialectical model of argumentation analysis, this paper illustrates how a modern approach can be used for Galatians. It is argued that by using a sophisticated method we can gain a more accurate understanding of Paul’s argumentation
Non-perturbative plaquette in 3d pure SU(3)
We present a determination of the elementary plaquette and, after the
subsequent ultraviolet subtractions, of the finite part of the gluon
condensate, in lattice regularization in three-dimensional pure SU(3) gauge
theory. Through a change of regularization scheme to MSbar and a matching back
to full four-dimensional QCD, this result determines the first non-perturbative
contribution in the weak-coupling expansion of hot QCD pressure.Comment: 6 pages, 4 figures, talk presented at Lattice 2005 (Non-zero
temperature and density
Three-dimensional physics and the pressure of hot QCD
We update Monte Carlo simulations of the three-dimensional SU(3) + adjoint
Higgs theory, by extrapolating carefully to the infinite volume and continuum
limits, in order to estimate the contribution of the infrared modes to the
pressure of hot QCD. The sum of infrared contributions beyond the known 4-loop
order turns out to be a smooth function, of a reasonable magnitude and specific
sign. Unfortunately, adding this function to the known 4-loop terms does not
improve the match to four-dimensional lattice data, in spite of the fact that
other quantities, such as correlation lengths, spatial string tension, or quark
number susceptibilities, work well within the same setup. We outline possible
ways to reduce the mismatch.Comment: 14 page
Minimal Flavor Constraints for Technicolor
We analyze the constraints on the the vacuum polarization of the standard
model gauge bosons from a minimal set of flavor observables valid for a general
class of models of dynamical electroweak symmetry breaking. We will show that
the constraints have a strong impact on the self-coupling and masses of the
lightest spin-one resonances. Our analysis is applicable to any four and higher
dimensional extension of the standard model reducing to models of dynamical
electroweak symmetry breaking.Comment: 26 pages, we have added appendix C and some references and corrected
some typo
Plaquette expectation value and lattice free energy of three-dimensional SU(N) gauge theory
We use high precision lattice simulations to calculate the plaquette
expectation value in three-dimensional SU(N) gauge theory for N=2,3,4,5,8.
Using these results, we study the N-dependence of the first non-perturbative
coefficient in the weak-coupling expansion of hot QCD. We demonstrate that, in
the limit of large N, the functional form of the plaquette expectation value
with ultraviolet divergences subtracted is 15.9(2)-44(2)/N^2.Comment: 14 pages, 6 figures. v2: references added; published versio
The Electroweak Phase Transition in Ultra Minimal Technicolor
We unveil the temperature-dependent electroweak phase transition in new
extensions of the Standard Model in which the electroweak symmetry is
spontaneously broken via strongly coupled, nearly-conformal dynamics achieved
by the means of multiple matter representations. In particular, we focus on the
low energy effective theory introduced to describe Ultra Minimal Walking
Technicolor at the phase transition. Using the one-loop effective potential
with ring improvement, we identify regions of parameter space which yield a
strong first order transition. A striking feature of the model is the existence
of a second phase transition associated to the electroweak-singlet sector. The
interplay between these two transitions leads to an extremely rich phase
diagram.Comment: 38 RevTeX pages, 9 figure
Eye contact with neutral and smiling faces: effects on autonomic responses and frontal EEG asymmetry
In our previous studies we have shown that seeing another person “live” with a direct vs. averted gaze results in enhanced skin conductance responses (SCRs) indicating autonomic arousal and in greater relative left-sided frontal activity in the electroencephalography (asymmetry in the alpha-band power), associated with approach motivation. In our studies, however, the stimulus persons had a neutral expression. In real-life social interaction, eye contact is often associated with a smile, which is another signal of the sender's approach-related motivation. A smile could, therefore, enhance the affective-motivational responses to eye contact. In the present study, we investigated whether the facial expression (neutral vs. social smile) would modulate autonomic arousal and frontal EEG alpha-band asymmetry to seeing a direct vs. an averted gaze in faces presented “live” through a liquid crystal (LC) shutter. The results showed that the SCRs were greater for the direct than the averted gaze and that the effect of gaze direction was more pronounced for a smiling than a neutral face. However, in this study, gaze direction and facial expression did not affect the frontal EEG asymmetry, although, for gaze direction, we found a marginally significant correlation between the degree of an overall bias for asymmetric frontal activity and the degree to which direct gaze elicited stronger left-sided frontal activity than did averted gaze
Impact of land cover change on aboveground carbon stocks in Afromontane landscape in Kenya
Land cover change takes place in sub-Saharan Africa as forests and shrublands are converted to agricultural lands in order to meet the needs of growing population. Changes in land cover also impact carbon sequestration in vegetation cover with an influence on climate on continental scale. The impact of land cover change on tree aboveground carbon stocks was studied in Taita Hills, Kenya. The land cover change between 1987 and 2011 for four points of time was assessed using SPOT satellite imagery, while the carbon density in various land cover types was assessed with field measurements, allometric biomass functions and airborne laser scanning data. Finally, the mean carbon densities of land cover types were combined with land cover maps resulting in carbon stock values for given land cover types for each point of time studied. Expansion of croplands has been taking place since 1987 and before on the cost of thickets and shrublands, especially on the foothills and lowlands. Due to the land cover changes, the carbon stock of trees was decreasing until 2003, after which there has been an increase. The findings of the research is supported by forest transition model, which emphasizes increase of awareness of forests' role in providing ecosystem services, such as habitats for pollinators, water harvesting and storage at the same time when economic reasons in making land-use choices between cropland and woodland, and governmental legislation supports trees on farms.Land cover change takes place in sub-Saharan Africa as forests and shrublands are converted to agricultural lands in order to meet the needs of growing population. Changes in land cover also impact carbon sequestration in vegetation cover with an influence on climate on continental scale. The impact of land cover change on tree aboveground carbon stocks was studied in Taita Hills, Kenya. The land cover change between 1987 and 2011 for four points of time was assessed using SPOT satellite imagery, while the carbon density in various land cover types was assessed with field measurements, allometric biomass functions and airborne laser scanning data. Finally, the mean carbon densities of land cover types were combined with land cover maps resulting in carbon stock values for given land cover types for each point of time studied. Expansion of croplands has been taking place since 1987 and before on the cost of thickets and shrublands, especially on the foothills and lowlands. Due to the land cover changes, the carbon stock of trees was decreasing until 2003, after which there has been an increase. The findings of the research is supported by forest transition model, which emphasizes increase of awareness of forests' role in providing ecosystem services, such as habitats for pollinators, water harvesting and storage at the same time when economic reasons in making land-use choices between cropland and woodland, and governmental legislation supports trees on farms.Peer reviewe
Seasonal cycle of benthic denitrification and DNRA in the aphotic coastal zone, northern Baltic Sea
Current knowledge on the seasonality of benthic nitrate reduction pathways in the aphotic, density stratified coastal zone of the Baltic Sea is largely based on data from muddy sediments, neglecting the potential contribution of sandy sediments. To gain a more comprehensive understanding of seasonality in this part of the Baltic Sea coast, we measured rates of benthic denitrification, anammox and dissimilatory nitrate reduction to ammonium (DNRA) monthly in the ice-free period of 2016 in both sandy and muddy aphotic sediments, northwestern Gulf of Finland. No anammox was observed. The seasonal cycle of denitrification in both sediment types was related to the hydrography-driven development of bottom water temperature. The seasonal cycle of DNRA was less clear and likely connected to a combination of bottom water temperature, carbon to nitrogen ratio, and substrate competition with denitrification. Denitrification and DNRA rates were 50-80 and 20% lower in the sandy than in the muddy sediment. The share of DNRA in total nitrate reduction, however, was higher in the sandy than in the muddy sediment, being (by similar to 50%) the highest DNRA share in sandy sediments so far measured. Our data add to the small pool of published studies showing significant DNRA in both cold and/or sandy sediments and suggest that DNRA is currently underestimated in the Baltic coastal nitrogen filter. Our results furthermore emphasize that the various environmental conditions of a coastal habitat (light regime, hydrography, and geomorphology) affect biogeochemical element cycling and thus need to be considered in data interpretation.Peer reviewe
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