5,989 research outputs found
Vacuum decay in an interacting multiverse
We examine a new multiverse scenario in which the component universes
interact. We focus our attention to the process of "true" vacuum nucleation in
the false vacuum within one single element of the multiverse. It is shown that
the interactions lead to a collective behaviour that might lead, under specific
conditions, to a pre-inflationary phase and ensued distinguishable imprints in
the comic microwave background radiation.Comment: 9 pages, 5 figure
Weak boson production measured in PbPb and pp collisions by CMS
The unprecedented center-of-mass energy available at the LHC offers unique
opportunities for studying the properties of the strongly-interacting QCD
matter created in PbPb collisions at extreme temperatures and very low parton
momentum fractions. Electroweak boson production is an important benchmark
process at hadron colliders. Precise measurements of Z production in heavy-ion
collisions can help to constrain nuclear PDFs as well as serve as a standard
candle of the initial state in PbPb collisions at the LHC energies. The
inclusive and differential measurements of the Z boson yield in the muon decay
channel will be presented, establishing that no modification is observed with
respect to next-to-leading order pQCD calculations, scaled by the number of
incoherent nucleon-nucleon collisions. The status of the Z measurement in the
electron decay channel, as well as the first observation of W \rightarrow \mu
{\nu} in heavy ion collisions will be given. The heavy-ion results will be
presented in the context of those obtained in pp collisions with the CMS
detector.Comment: Quark Matter 2011 conference proceeding
Estudio de las opiniones CTS entre profesores del bachillerato y universitarios de QuÃmica
Dentro del Proyecto Iberoamericano de Evaluación de Actitudes Relacionadas con la Ciencia, la TecnologÃa y la Sociedad (PIEARCTS), este grupo de investigadores vamos a centrarnos en verter las opiniones sobre las relaciones Ciencia-TecnologÃa-Sociedad (CTS) de profesores de dos niveles educativos públicos: el bachillerato y el profesional. Nuestra conclusión más importante es que encontramos una visión inadecuada relativamente similar en las dos muestras. Sin embargo hallamos diferencias en los aspectos más sociales de la NdC (en los que el profesorado del bachillerato tiene una mejor evaluación) y en los de definición cientÃfica (en los que están mejor los profesores del nivel profesional). Los dos grupos tuvieron visiones inadecuadas tanto en lo referente a la tecnologÃa, a los aspectos de género, como en los factores epistemológicos
Decoherence in an accelerated universe
In this paper we study the decoherence processes of the semiclassical
branches of an accelerated universe due to their interaction with a scalar
field with given mass. We use a third quantization formalism to analyze the
decoherence between two branches of a parent universe caused by their
interaction with the vaccum fluctuations of the space-time, and with other
parent unverses in a multiverse scenario.Comment: 11 pages, 2 figure
Collaboration and Innovation Dynamics in Software Ecosystems: A Technology Management Research Perspective
ALMA Observations of Gas-Rich Galaxies in z~1.6 Galaxy Clusters: Evidence for Higher Gas Fractions in High-Density Environments
We present ALMA CO (2-1) detections in 11 gas-rich cluster galaxies at z~1.6,
constituting the largest sample of molecular gas measurements in z>1.5 clusters
to date. The observations span three galaxy clusters, derived from the Spitzer
Adaptation of the Red-sequence Cluster Survey. We augment the >5sigma
detections of the CO (2-1) fluxes with multi-band photometry, yielding stellar
masses and infrared-derived star formation rates, to place some of the first
constraints on molecular gas properties in z~1.6 cluster environments. We
measure sizable gas reservoirs of 0.5-2x10^11 solar masses in these objects,
with high gas fractions and long depletion timescales, averaging 62% and 1.4
Gyr, respectively. We compare our cluster galaxies to the scaling relations of
the coeval field, in the context of how gas fractions and depletion timescales
vary with respect to the star-forming main sequence. We find that our cluster
galaxies lie systematically off the field scaling relations at z=1.6 toward
enhanced gas fractions, at a level of ~4sigma, but have consistent depletion
timescales. Exploiting CO detections in lower-redshift clusters from the
literature, we investigate the evolution of the gas fraction in cluster
galaxies, finding it to mimic the strong rise with redshift in the field. We
emphasize the utility of detecting abundant gas-rich galaxies in high-redshift
clusters, deeming them as crucial laboratories for future statistical studies.Comment: 8 pages, 3 figures, published in ApJ Letters; updated to match
published versio
Belnap-Dunn semantics for natural implicative expansions of Kleene's strong three-valued matrix with two designated values
27 p.A conditional is natural if it fulfils the three following conditions. (1) It coincides with the classical conditional when restricted to the classical values T and F; (2) it satisfies the Modus Ponens; and (3) it is assigned a designated value whenever the value assigned to its antecedent is less than or equal to the value assigned to its consequent. The aim of this paper is to provide a ‘bivalent’ Belnap-Dunn semantics for all natural implicative expansions of Kleene's strong 3-valued matrix with two designated elements. (We understand the notion ‘natural conditional’ according to N. Tomova, ‘A lattice of implicative extensions of regular Kleene's logics’, Reports on Mathematical Logic, 47, 173–182, 2012.)S
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