95 research outputs found
Beta decays and the inner structures of the neutrino in a NLHV design
A novel conceptual theory is developed for the beta decay and electron capture processes, based on the specific non-local hidden-variable (NLHV) design provided by the Cordus theory. A new mechanics is sketched out for the interactions of particules through their discrete forces, and is a deeper level representation of Feynman diagrams. The new mechanics is able to correctly predict the outcomes of the decay processes, beta minus, beta plus, electron capture. It predicts specific NLHV structures for the neutrino and antineutrino. The velocity and unique spins of the neutrino species may then be explained as a consequence of the hidden structures
Hidden variable theory supports variability in decay rates of nuclides
PROBLEM- The orthodox expectation is for decay rates to be strictly constant for all types of decay (β+, β-, EC, ⍺). However empirical results show strong evidence for nuclides having variable decay rates, typically evident as periodicity. The volume of data available suggests this is a real phenomenon, not merely a spurious outcome of measurement errors. However the problem is complex because the data are conflicted for different decays. Furthermore, there is no coherent theory for why the phenomenon should exist in the first place. The effect is not required or predicted by quantum theory. Consequently it is a significant challenge to explain how the variability might arise, what factors could be involved, and how the underlying mechanisms of causality might operate. This lack of explanation contributes to the phenomenon often being dismissed as erroneous. PURPOSE- This paper develops a theoretical explanation of the variability of nuclide decay rates. APPROACH- The non-local hidden-variable solution provided by the Cordus theory was used, specifically its mechanics for neutrino-species interactions with nucleons. FINDINGS- It is predicted that the β-, β+ and electron capture processes are induced by pre-supply of neutrino-species, and that the effects are asymmetrical for those species. Also predicted is that different input energies are required, i.e. that a threshold effect exists. Four simple non-contentious lemmas are proposed with which it is straightforward to explain why β- and EC would be enhanced and correlate to solar neutrino flux (proximity & activity), and a emission unaffected. It is shown that the concept of a neutrino-species asymmetry makes sense of the broad patterns evident in the empirical data. IMPLICATIONS- The results support the variability of decay rates, on theoretical grounds. The type of decay (β+, β-, EC, ⍺) is found to be a key variable in this theory, as is the type of neutrino species and its energy. Past experiments have generally not recorded the variables sufficiently. Future empirical tests of nuclide decay rates need to be more specific about the identity of the external environmental, neutrino-species, both the energy and flux thereof. It is also necessary to be more specific about the decay path. The different decays have to be considered separately, not lumped together, nor classified primarily by element (e.g. U, Pb, Cl, etc.) but rather by type of decay process (β+, β-, EC, ⍺). A more radical implication is that hidden-variable theories offer profoundly new perspectives on fundamental physics, and can explain complex phenomena that are inconceivable from within the zero-dimensional point framework of quantum theory. ORIGINALITY- The novel contribution is the provision of a theoretical explanation for why decay rates would be variable. A detailed mechanism is presented for neutrino-species induced decay. Also novel is the prediction that the interaction is asymmetrical, and that the energy requirements are different for the various types of decay. The explanation is qualitatively consistent with the empirical evidence
Neutron star cooling: Theoretical aspects and observational constraints
The cooling theory of isolated neutron stars is reviewed. The main cooling
regulators are discussed, first of all, operation of direct Urca process (or
similar processes in exotic phases of dense matter) and superfluidity in
stellar interiors. The prospects to constrain gross parameters of supranuclear
matter in neutron-star interiors by confronting cooling theory with
observations of isolated neutron stars are outlined. A related problem of
thermal states of transiently accreting neutron stars with deep crustal heating
of accreted matter is discussed in application to soft X-ray transients.Comment: 10 pages, 3 figures, Proceedings of the 34th COSPAR Scientific
Assembly (Adv. Sp. Res., accepted
Pulsar kicks from a dark-matter sterile neutrino
We show that a sterile neutrino with mass in the 1-20 keV range and a small
mixing with the electron neutrino can simultaneously explain the origin of the
pulsar motions and the dark matter in the universe. An asymmetric neutrino
emission from a hot nascent neutron star can be the explanation of the observed
pulsar velocities. In addition to the pulsar kick mechanism based on resonant
neutrino transitions, we point out a new possibility: an asymmetric
off-resonant emission of sterile neutrinos. The two cases correspond to
different values of the masses and mixing angles. In both cases we identify the
ranges of parameters consistent with the pulsar kick, as well as cosmological
constraints.Comment: 5 pages, 2 figures; final version; discussion and references adde
The Magnificent Seven: Magnetic fields and surface temperature distributions
Presently seven nearby radio-quiet isolated neutron stars discovered in ROSAT
data and characterized by thermal X-ray spectra are known. They exhibit very
similar properties and despite intensive searches their number remained
constant since 2001 which led to their name ``The Magnificent Seven''. Five of
the stars exhibit pulsations in their X-ray flux with periods in the range of
3.4 s to 11.4 s. XMM-Newton observations revealed broad absorption lines in the
X-ray spectra which are interpreted as cyclotron resonance absorption lines by
protons or heavy ions and / or atomic transitions shifted to X-ray energies by
strong magnetic fields of the order of 10^13 G. New XMM-Newton observations
indicate more complex X-ray spectra with multiple absorption lines. Pulse-phase
spectroscopy of the best studied pulsars RX J0720.4-3125 and RBS 1223 reveals
variations in derived emission temperature and absorption line depth with pulse
phase. Moreover, RX J0720.4-3125 shows long-term spectral changes which are
interpreted as due to free precession of the neutron star. Modeling of the
pulse profiles of RX J0720.4-3125 and RBS 1223 provides information about the
surface temperature distribution of the neutron stars indicating hot polar caps
which have different temperatures, different sizes and are probably not located
in antipodal positions.Comment: 10 pages, 8 figures, to appear in Astrophysics and Space Science, in
the proceedings of "Isolated Neutron Stars: from the Interior to the
Surface", edited by D. Page, R. Turolla and S. Zan
Cooling of Neutron Stars with Strong Toroidal Magnetic Fields
We present models of temperature distribution in the crust of a neutron star in the presence of a strong toroidal component superposed to the poloidal component of the magnetic field. The presence of such a toroidal field hinders heat flow toward the surface in a large part of the crust. As a result, the neutron star surface presents two warm regions surrounded by extended cold regions and has a thermal luminosity much lower than in the case the magnetic field is purely poloidal. We apply these models to calculate the thermal evolution of such neutron stars and show that the lowered photon luminosity naturally extends their life-time as detectable thermal X-ray sources
Dynamical complexity in the C.elegans neural network
We model the neuronal circuit of the C.elegans soil worm in terms of a Hindmarsh-Rose system of ordinary differential equa- tions, dividing its circuit into six communities which are determined via the Walktrap and Louvain methods. Using the numerical solution of these equations, we analyze important measures of dynamical com- plexity, namely synchronicity, the largest Lyapunov exponent, and the ?AR auto-regressive integrated information theory measure. We show that ?AR provides a useful measure of the information contained in the C.elegans brain dynamic network. Our analysis reveals that the C.elegans brain dynamic network generates more information than the sum of its constituent parts, and that attains higher levels of integrated information for couplings for which either all its communities are highly synchronized, or there is a mixed state of highly synchronized and de- synchronized communities
Magnetic Field Generation in Stars
Enormous progress has been made on observing stellar magnetism in stars from
the main sequence through to compact objects. Recent data have thrown into
sharper relief the vexed question of the origin of stellar magnetic fields,
which remains one of the main unanswered questions in astrophysics. In this
chapter we review recent work in this area of research. In particular, we look
at the fossil field hypothesis which links magnetism in compact stars to
magnetism in main sequence and pre-main sequence stars and we consider why its
feasibility has now been questioned particularly in the context of highly
magnetic white dwarfs. We also review the fossil versus dynamo debate in the
context of neutron stars and the roles played by key physical processes such as
buoyancy, helicity, and superfluid turbulence,in the generation and stability
of neutron star fields.
Independent information on the internal magnetic field of neutron stars will
come from future gravitational wave detections. Thus we maybe at the dawn of a
new era of exciting discoveries in compact star magnetism driven by the opening
of a new, non-electromagnetic observational window.
We also review recent advances in the theory and computation of
magnetohydrodynamic turbulence as it applies to stellar magnetism and dynamo
theory. These advances offer insight into the action of stellar dynamos as well
as processes whichcontrol the diffusive magnetic flux transport in stars.Comment: 41 pages, 7 figures. Invited review chapter on on magnetic field
generation in stars to appear in Space Science Reviews, Springe
Neutrino Cooling of Neutron Stars. Medium effects
This review demonstrates that neutrino emission from dense hadronic component
in neutron stars is subject of strong modifications due to collective effects
in the nuclear matter. With the most important in-medium processes incorporated
in the cooling code an overall agreement with available soft X ray data can be
easily achieved. With these findings so called "standard" and "non-standard"
cooling scenarios are replaced by one general "nuclear medium cooling scenario"
which relates slow and rapid neutron star coolings to the star masses (interior
densities). In-medium effects take important part also at early hot stage of
neutron star evolution decreasing the neutrino opacity for less massive and
increasing for more massive neutron stars. A formalism for calculation of
neutrino radiation from nuclear matter is presented that treats on equal
footing one-nucleon and multiple-nucleon processes as well as reactions with
resonance bosons and condensates. Cooling history of neutron stars with quark
cores is also discussed.Comment: To be published in "Physics of Neutron Star Interiors", Eds. D.
Blaschke, N.K. Glendenning, A. Sedrakian, Springer, Heidelberg (2001
Espécies crípticas em Pagamea coriacea sensu lato (Rubiaceae): evidências morfológicas, ecológicas e de comportamento reprodutivo em um contexto simpátrico
In this study we explore morphological and ecological variation in sympatric populations of Pagamea coriacea s.l. - a species complex from white-sand vegetation in the Amazon. A total of 147 trees were sampled and monitored at three nearby sites in Central Amazon, Brazil. Multivariate analyses of morphology indicated two distinct groups (A and B), which also differed in bark type, each containing subgroups associated with sexual dimorphism. However, a single hermaphroditic individual was observed within group B. As expected, all pistillate plants produced fruits, but 23% of the staminate plants of group B, and 5% of group A also produced fruits. This variation suggests that the sexual systems of both groups are between dioecy and gynodioecy. There was an overlap in flowering phases between the two groups, but the pattern of floral maturation differed. Ecologically, plants of group B were found in more shaded habitats and over sandstone bedrocks, while group A was prevalent in deeper sandy soils as canopy plants. The significances of morphological and environmental differences were tested by a multivariate analysis of variance, and a canonical discriminant analysis assessed the importance of variables. The coexistence in sympatry of two discrete morphological groups in the P. coriacea s.l., with different habitat preferences and reproductive behaviors, indicates they represent distinct species.O objetivo deste estudo foi testar se o complexo de espécies Pagamea coriacea inclui múltiplas espécies, usando evidências morfológicas, ecológicas e de comportamento reprodutivo. Um total de 147 árvores foram amostradas e monitoradas em três locais próximos na Amazônia Central, Brasil. Análises multivariadas de dados morfológicos indicaram dois grupos discretos (A e B), que coincidem com diferenças no tipo de casca, cada um por sua vez com subgrupos que representam dimorfismo sexual. Contudo, um indivíduo distintamente hermafrodita foi encontrado no grupo B. Todas as plantas pistiladas produziram frutos, mas também foram observados frutos para 23% das plantas estaminadas do grupo B, e para 5% das estaminadas do grupo A. Essa variação sugere que ambos grupos possuem um sistema sexual entre dioicia e ginodioicia. Houve sobreposição das fases de floração e frutificação entre os dois grupos, mas o padrão de maturação de flores foi diferente. Quanto ao hábitat, o grupo B predominou em situações de sombra e em solos arenosos rasos sobre lajes de pedra, enquanto o grupo A ocorreu em solos arenosos mais profundos e no dossel da vegetação. A coexistência de dois grupos morfológicos discretos no complexo P. coriacea s.l., com diferenças ecológicas e de comportamento reprodutivo, indica que correspondem a duas espécies distintas
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