3,351 research outputs found
Phase structure of the N=1 supersymmetric Yang-Mills theory at finite temperature
Supersymmetry (SUSY) has been proposed to be a central concept for the
physics beyond the standard model and for a description of the strong
interactions in the context of the AdS/CFT correspondence. A deeper
understanding of these developments requires the knowledge of the properties of
supersymmetric models at finite temperatures. We present a Monte Carlo
investigation of the finite temperature phase diagram of the N=1 supersymmetric
Yang-Mills theory (SYM) regularised on a space-time lattice. The model is in
many aspects similar to QCD: quark confinement and fermion condensation occur
in the low temperature regime of both theories. A comparison to QCD is
therefore possible. The simulations show that for N=1 SYM the deconfinement
temperature has a mild dependence on the fermion mass. The analysis of the
chiral condensate susceptibility supports the possibility that chiral symmetry
is restored near the deconfinement phase transition.Comment: 26 pages, 12 figure
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Behaviour change at work: Empowering energy efficiency in the workplace through user-centred design
Copyright @ 2011 University of California eScholarship RepositoryCO2 emissions from non-domestic buildings - primarily workplaces - make up 18 percent of the UK's carbon footprint. A combination of technology advances and behavioural changes have the potential to make significant impact, but interventions have often been planned in ways which do not take into account the needs, levels of understanding and everyday behavioural contexts of building users - and hence do not achieve the hoped-for success.This paper provides a brief introduction to the Empower project, a current industrial-academic collaboration in the UK which is applying methods from user-centred design practice to understand diverse users' needs, priorities, mental models of energy and decision-making heuristics - as well as the affordances available to them - in a number of office buildings. We are developing and trialling a set of low-cost, simple software interventions tailored to multiple user groups with different degrees of agency over their energy use, which seek to influence more energy efficient behaviour at work in areas such as HVAC, lighting and equipment use. The project comprises an ethnographic research phase, a participatory design programme involving building users in the design of interventions, and iterative trials in a large office building in central London
Growing points in attachment disorganization: Looking back to advance forward
In this special issue paper we reflect on the next generation of attach- ment research with a focus on disorganization, a central but still poorly understood topic in this area. We suggest that progress will be facili- tated by a return to attachment theory’s evolutionary roots, and to the emphasis on biological function that inspired Bowlby’s original thinking. Increased interdisciplinary cross-fertilization and collaborations would enable novel and generative research on some of the long-standing questions surrounding attachment disorganization. Accordingly, we present an agenda for future research that encompasses contributions of modern ethology and neurobiology, novel hypotheses based on the concept of adaptive decanalization, connections with neurodevelop- mental vulnerability and risk for mental disorders such as schizophrenia, and the possibility of sex differences in the behavioral manifestations of attachment disorganization. We believe that these avenues of theory and research offer exciting potential for innovative work in attachment disorganization in the years ahead
Implications of gauge-mediated supersymmetry breaking with vector-like quarks and a ~125 GeV Higgs boson
We investigate the implications of models that achieve a Standard Model-like
Higgs boson of mass near 125 GeV by introducing additional TeV-scale
supermultiplets in the vector-like 10+\bar{10} representation of SU(5), within
the context of gauge-mediated supersymmetry breaking. We study the resulting
mass spectrum of superpartners, comparing and contrasting to the usual
gauge-mediated and CMSSM scenarios, and discuss implications for LHC
supersymmetry searches. This approach implies that exotic vector-like fermions
t'_{1,2}, b',and \tau' should be within the reach of the LHC. We discuss the
masses, the couplings to electroweak bosons, and the decay branching ratios of
the exotic fermions, with and without various unification assumptions for the
mass and mixing parameters. We comment on LHC prospects for discovery of the
exotic fermion states, both for decays that are prompt and non-prompt on
detector-crossing time scales.Comment: 32 pages. v2: references added, figure caption 5.3 correcte
Renormalization of the nonequilibrium dynamics of fermions in a flat FRW universe
We derive the renormalized equations of motion and the renormalized
energy-momentum tensor for fermions coupled to a spatially homogeneous scalar
field (inflaton) in a flat FRW geometry. The fermion back reaction to the
metric and to the inflaton field is formulated in one-loop approximation.
Having determined the infinite counter terms in an scheme we
formulate the finite terms in a form suitable for numerical computation. We
comment on the trace anomaly which is inferred from the standard analysis. We
also address the problem of initial singularities and determine the Bogoliubov
transformation by which they are removed.Comment: 26 pages, LaTe
Comparing Map Learning between Touchscreen-Based Visual and Haptic Displays: A Behavioral Evaluation with Blind and Sighted Users
The ubiquity of multimodal smart devices affords new opportunities for eyes-free applications for conveying graphical information to both sighted and visually impaired users. Using previously established haptic design guidelines for generic rendering of graphical content on touchscreen interfaces, the current study evaluates the learning and mental representation of digital maps, representing a key real-world translational eyes-free application. Two experiments involving 12 blind participants and 16 sighted participants compared cognitive map development and test performance on a range of spatio-behavioral tasks across three information-matched learning-mode conditions: (1) our prototype vibro-audio map (VAM), (2) traditional hardcopy-tactile maps, and (3) visual maps. Results demonstrated that when perceptual parameters of the stimuli were matched between modalities during haptic and visual map learning, test performance was highly similar (functionally equivalent) between the learning modes and participant groups. These results suggest equivalent cognitive map formation between both blind and sighted users and between maps learned from different sensory inputs, providing compelling evidence supporting the development of amodal spatial representations in the brain. The practical implications of these results include empirical evidence supporting a growing interest in the efficacy of multisensory interfaces as a primary interaction style for people both with and without vision. Findings challenge the long-held assumption that blind people exhibit deficits on global spatial tasks compared to their sighted peers, with results also providing empirical support for the methodological use of sighted participants in studies pertaining to technologies primarily aimed at supporting blind users
Brane world models need low string scale
Models with large extra dimensions offer the possibility of the Planck scale being of order the electroweak scale, thus alleviating the gauge hierarchy problem. We show that these models suffer from a breakdown of unitarity at around three quarters of the low effective Planck scale. An obvious candidate to fix the unitarity problem is string theory. We therefore argue that it is necessary for the string scale to appear below the effective Planck scale and that the first signature of such models would be string resonances. We further translate experimental bounds on the string scale into bounds on the effective Planck scale
Strategies to identify muscle fatigue from SEMG during cycling
Detection, quantification and analysis of muscle fatigue are crucial in occupational/rehabilitation and sporting settings. Sports organizations, such as the Australian Institute of Sports (AIS), currently monitor fatigue by a battery of tests including invasive techniques that require taking blood samples and/or muscle biopsies, the latter of which is highly invasive, painful, time consuming and expensive. SEMG (surface electromyography) is non-invasive monitoring of muscle activation and is an indication of localized muscle fatigue based on the observed shift of the power spectral density of the SEMG. The success of SEMG based techniques is currently limited to isometric contraction and is not acceptable to the human movement community. The paper proposes and tests a simple signal processing technique to identify the onset of muscle fatigue during cyclic activities of muscles, such as VL and VM, during cycling. Based on experiments conducted with 7 participants, using power output as a measure of fatigue, the technique is able to identify muscle fatigue with 98% significance
Observable Electron EDM and Leptogenesis
In the context of the minimal supersymmetric seesaw model, the CP-violating
neutrino Yukawa couplings might induce an electron EDM. The same interactions
may also be responsible for the generation of the observed baryon asymmetry of
the Universe via leptogenesis. We identify in a model-independent way those
patterns within the seesaw models which predict an electron EDM at a level
probed by planned laboratory experiments and show that negative searches on
\tau-> e \gamma decay may provide the strongest upper bound on the electron
EDM. We also conclude that a possible future detection of the electron EDM is
incompatible with thermal leptogenesis, even when flavour effects are accounted
for.Comment: 26 pages, 6 figure
Relativistic Turbulence: A Long Way from Preheating to Equilibrium
We study, both numerically and analytically, the development of equilibrium
after preheating. We show that the process is characterised by the appearance
of Kolmogorov spectra and the evolution towards thermal equilibrium follows
self-similar dynamics. Simplified kinetic theory gives values for all
characteristic exponents which are close to what is observed in lattice
simulations. The resulting time for thermalization is long, and temperature at
thermalization is low, eV in the simple
inflationary model. Our results allow a straightforward generalization to
realistic models.Comment: 4 pages, 3figures, LaTe
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