1,841 research outputs found
The angular power spectrum of radio emission at 2.3 GHz
We have analysed the Rhodes/HartRAO survey at 2326 MHz and derived the global
angular power spectrum of Galactic continuum emission. In order to measure the
angular power spectrum of the diffuse component, point sources were removed
from the map by median filtering. A least-square fit to the angular power
spectrum of the entire survey with a power law spectrum C_l proportional to
l^{-alpha}, gives alpha = 2.43 +/- 0.01 for l = 2-100. The angular power
spectrum of radio emission appears to steepen at high Galactic latitudes and
for observed regions with |b| > 20 deg, the fitted spectral index is alpha =
2.92 +/- 0.07. We have extrapolated this result to 30 GHz (the lowest frequency
channel of Planck) and estimate that no significant contribution to the sky
temperature fluctuation is likely to come from synchrotron at degree-angular
scalesComment: 10 pages, 10 figures, accepted for publication by Astronomy &
Astrophysic
SMEFT and the Drell-Yan Process at High Energy
The Drell-Yan process is a copious source of lepton pairs at high energy and
is measured with great precision at the Large Hadron Collider (LHC). Barring
any new light particles, beyond the Standard Model effects can be studied in
Drell-Yan production using an effective field theory. At tree level, new
4-fermion interactions dominate, while at one loop operators modifying 3-gauge
boson couplings contribute effects that are enhanced at high energy. We study
the sensitivity of the neutral Drell-Yan process to these dimension-6 operators
and compare the sensitivity to that of pair production at the LHC.Comment: 13 pages, 4 figures. v2: version accepted for publication in PR
Past-directed scalar field gradients and scalar-tensor thermodynamics
We refine and slightly enlarge the recently proposed first-orderthermodynamics of scalar-tensor gravity to include gravitational scalar fieldswith timelike and past-directed gradients. The implications and subtletiesarising in this situation are discussed and an exact cosmological solution ofscalar-tensor theory in first-order thermodynamics is revisited in light ofthese results.<br
Analysis of CMB foregrounds using a database for Planck
Within the scope of the Planck IDIS (Integrated Data Information System)
project we have started to develop the data model for time-ordered data and
full-sky maps. The data model is part of the Data Management Component (DMC), a
software system designed according to a three-tier architecture which allows
complete separation between data storage and processing. The DMC is already
being used for simulation activities and the modeling of some foreground
components. We have ingested several Galactic surveys into the database and
used the science data-access interface to process the data. The data structure
for full-sky maps utilises the HEALPix tessellation of the sphere. We have been
able to obtain consistent measures of the angular power spectrum of the
Galactic radio continuum emission between 408 MHz and 2417 MHz.Comment: 7 pages, 6 figures. To appear in the Proceedings of the MPA/ESO/MPE
Joint Astronomy Conference "Mining The Sky
Wave effects on the morphodynamic evolution of an offshore sand bank
The origin and morphodynamic evolution of linear sand banks have been widely studied in recent years. Several investigations have been carried out in order to understand the influence of tide-related parameters, bathymetry and Coriolis force on sand bank formation and maintenance. However, the effect of waves on the net flux of sediments over the sand banks has often been neglected on grounds of the short duration of significant wave activity compared to that of tidal cycles. Nevertheless, the interaction between wave activity and tidal currents leads to a high increase of bottom shear stress, especially at the sand bank crests and, as a consequence, to an increase of sand tranport. This paper investigates the effects of wave activity on the morphology and morphodynamics of the Kwinte Bank (Belgian shelf). Numerical simulations were carried out under different wave conditions to assess wave influence on sand bank evolution. Model verification involved analysis and comparison with field data collected during two different periods. The study shows that wave activity is not only responsible for a large increase in sediment transport but also for a change in direction of the net flux of sediments. Moreover, the morphological analysis of several sand banks supports the idea that wave activity might also have an impact on the shape of these sand banks. Wave climate data can be used to study long-term sand bank dynamics
Scalar field as a perfect fluid: thermodynamics of minimally coupled scalars and Einstein frame scalar-tensor gravity
We revisit the analogy between a minimally coupled scalar field in general relativity and a perfect fluid, correcting previous identifications of effective temperature and chemical potential. This provides a useful complementary picture for the first-order thermodynamics of scalar-tensor gravity, paving the way for the Einstein frame formulation (which eluded previous attempts) and raises interesting questions to further develop the analogy
Affect and Cognition in Managerial Decision Making: A Systematic Literature Review of Neuroscience Evidence
How do affect and cognition interact in managerial decision making? Over the last decades, scholars have investigated how managers make decisions. However, what remains largely unknown is the interplay of affective states and cognition during the decision-making process. We offer a systematization of the contributions produced on the role of affect and cognition in managerial decision making by considering the recent cross-fertilization of management studies with the neuroscience domain. We implement a Systematic Literature Review of 23 selected contributions dealing with the role of affect and cognition in managerial decisions that adopted neuroscience techniques/points of view. Collected papers have been analyzed by considering the so-called reflexive (X-) and reflective (C-) systems in social cognitive neuroscience and the type of decisions investigated in the literature. Results obtained help to support an emerging “unified” mind processing theory for which the two systems of our mind are not in conflict and for which affective states have a driving role toward cognition. A research agenda for future studies is provided to scholars who are interested in advancing the investigation of affect and cognition in managerial decision making, also through neuroscience techniques – with the consideration that these works should be at the service of the behavioral strategy field
Holographic Technidilaton and LHC searches
We analyze in detail the phenomenology of a model of dynamical electroweak
symmetry breaking inspired by walking technicolor, by using the techniques of
the bottom-up approach to holography. The model admits a light composite scalar
state, the dilaton, in the spectrum. We focus on regions of parameter space for
which the mass of such dilaton is 125 GeV, and for which the bounds on the
precision electroweak parameter S are satisfied. This requires that the
next-to-lightest composite state is the techni-rho meson, with a mass larger
than 2.3 TeV. We compute the couplings controlling the decay rates of the
dilaton to two photons and to two (real or virtual) Z and W bosons. For generic
choices of the parameters, we find a suppression of the decay into heavy gauge
bosons, in respect to the analog decay of the standard-model Higgs. We find a
dramatic effect on the decay into photons, which can be both strongly
suppressed or strongly enhanced, the latter case corresponding to the large-N
regime of the dual theory. There is a correlation between this decay rate of
the dilaton into photons and the mass splitting between the techni-rho meson
and its axial-vector partner: if the decay is enhanced in respect to the
standard-model case, then the heavy spin-1 resonances are nearly degenerate in
mass, otherwise their separation in mass is comparable to the mass scale
itself.Comment: Very minor typos corrected. References adde
Constraints on the Universal Varying Yukawa Couplings: from SM-like to Fermiophobic
Varying the Standard Model (SM) fermion Yukawa couplings universally by a
generic positive scale factor (), we study the phenomenological fit to
the current available experimental results for the Higgs boson search at hadron
colliders. We point out that the Higgs production cross section and its decay
branching ratio to can be varied oppositely by to make
their product almost invariant. Thus, our scenario and the SM Higgs are
indistinguishable in the inclusive channel. The current
measurements on direct Yukawa coupling strength in the
channel are not precise enough to fix the scale factor . The most
promising is the vector-boson-fusion channel in which the CMS has already
observed possible suppression effect on the Yukawa couplings. Further more, the
global fit of the experimental data can get the optimal value by
introducing a suppression factor on the SM Yukawa couplings.Comment: 16 pages, 12 figures, 5 tables, update analysis is supplemente
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