Some astrophysical consequences of the newly introduced barytino (masseless fermions having baryon number, analogous to the massless neutrino having lepton number) are considered. It is pointed out that the existense of such particles would have interesting implications for understanding astrophysical enigmas like the violation of baryon number conservation in gravitational collapse into black holes and the observed baryon asymmetry of the Universe. 相似文献
There are indications that less than 10–3 of the spin-down energy of the millisecond pulsar PSR 1937+214 emerges as electromagnetic radiation. The implications of this result are discussed. The surface magnetic field would then be 107 G, making the pulsar optically undetectable, and casting aspersions on the accretion disc spin-up neutron star models for the pulsar. The pulsar should have an equatorial ellipticity 10–9, which can be accounted for if the equatorial magnetic field departs from axisymmetry by one part in 103. 相似文献
Summary: Experiments were carried out to study the salinity tolerance and the impact of salinity changes on ions and metabolite in the body of a marine penaeid prawn, Parapenaeopsis sculptilis. Juveniles of this prawn species have a comparatively wide range of salinity tolerance than adults. Juveniles can tolerate 60 … 100 %, but adults only 100 % seawater concentrations. Behavioural observations showed that the juvenile and adult prawns became inactive with decrease in seawater concentrations followed by paralysis and death. Death occurred probably due to failure of the neuromuscular system. A highly significant variation existed in the amount of sodium, potassium and calcium ions in juveniles as well as adults. Exposure to different seawater concentrations probably caused breakdown of the osmoregulatory mechanism in the prawn body. Protein and carbohydrate decreased in both juvenile and adult prawn body, with the decrease in seawater concentrations indicating the utilization of large amounts of protein and carbohydrate from the internal reserve. 相似文献
Cosmic structure formation is thought to occur as a bottom-up scenario, i.e. the lightest objects would have formed first. It has been suggested that the earliest structures to form could have been primordial planets. Here we propose the possibility of formation of primordial planets at high redshifts composed predominantly of dark matter (DM) particles, with planetary masses ranging from Neptune mass to asteroid mass. Most of these primordial DM planets could be free floating without being attached to a host star and a substantial fraction could be present in the halo contributing to the DM. Here we suggest that the flux of DM particles could be significantly reduced as substantial number of DM particles are now trapped in such objects, perhaps accounting for the negative results seen so far in the ongoing DM detection experiments.
Gravitational waves from mergers of black holes and neutron stars are now being detected by LIGO. Here we look at a new source of gravitational waves, i.e., a class of dark matter objects whose properties were earlier elaborated. We show that the frequency of gravitational waves and strains on the detectors from such objects (including their mergers) could be within the sensitivity range of LIGO. The gravitational waves from the possible mergers of these dark matter objects will be different from those produced by neutron star mergers in the sense that they will not be accompanied by electromagnetic radiation since dark matter does not couple with radiation.
Seismic-potential for the Andaman Arc System (AAS) is evaluated using a three-tier approach: (i) the seismic b-values derived using a revised and homogenized earthquake catalog for Mw ≥ 4.7, with uniform Mw, for the period 1964–2013 created from ISC Data, (ii) Free-air gravity-anomalies for AAS and their geologic interpretation and (iii) deep crustal structure from seismic reflection surveys and 3D seismic tomography results. Both long-term spatial b-value anomalies for the period 1964-2013 and temporal b-value anomalies for a shorter period (2002–2013) have been estimated. The b-value maps are interpreted in terms of the stress regime acting across AAS and stressed asperities inferred along the strike of AAS. Eight distinguishable seismic-zones are identified and their seismic potential is examined by temporal bvalue anomalies in producing moderate to large earthquakes. The latter demonstrates ‘low-high’ or ‘high-low’ couplet over years, and that a variation in b-value more than 20% compared to the previous year value is likely to produce an earthquake event with Mw ≥ 6.0. Some support to this interpretation comes from the regional Free-air gravity-anomalies and deep crustal structure interpreted from hypocentral distribution of earthquakes. The high b-values are seemingly associated with magma chambers or low velocity crust; creating asperity zones due to multiple batholithic intrusions at plate boundary. This geologic interpretation is evidenced by 3D P-wave seismic tomography and velocity heterogeneity study for AAS reported by us elsewhere. 相似文献
As is well known, black hole entropy is proportional to the area of the horizon suggesting a holographic principle wherein all degrees of freedom contributing to the entropy reside on the surface. In this note, we point out that large scale dark energy (such as a cosmological constant) constraining cosmic structures can imply a similar situation for the entropy of a hierarchy of such objects. 相似文献
The notion of gravitational charge is used to suggest a link in the Machian sense between fundamental interactions and cosmology. The observed values of the coupling constants of these interactions then give a definite value for the total mass of the Universe. 相似文献
The astrophysical importance of the negative positronium ion, detected recently in the laboratory, has been pointed out. It is found that the presence of Ps– ions will contribute additionally to the width of 0.511 -ray line formed by pair annihilation. The formation of Ps– ion from an aggregate of electrons, positrons and positronium results in a variable positron population in the 0.511 MeV -ray line source. 相似文献
A possible connection between MOND (Modification of Newtonian Dynamics) proposed as an alternative hypothesis to dark matter in galaxies and clusters and a residual cosmological constant term dominating cosmological dynamics in a = 1 universe is explored. 相似文献
