<正> From the k symmetric action of IIB string in AdS_2×S~2 background given by Zhou,we derive theequations of motion.By using the twisted dual transformation which was introduced by Hou,we construct the fl...<正> From the k symmetric action of IIB string in AdS_2×S~2 background given by Zhou,we derive theequations of motion.By using the twisted dual transformation which was introduced by Hou,we construct the flatcurrents,conserving non-local charge with one free parameter,for the superstring in AdS_2×S_2.展开更多
New better estimates, which are given in terms of elementary functions, for the function r →(2/π)(1 -r2)κ(r)κ′(r) + logr appearing in Hubner's sharp upper bound for the Hersch-Pfluger distortion functio...New better estimates, which are given in terms of elementary functions, for the function r →(2/π)(1 -r2)κ(r)κ′(r) + logr appearing in Hubner's sharp upper bound for the Hersch-Pfluger distortion function are obtained. With these estimates, some known bounds for the Hersch-Pfluger distortion function in quasiconformal theory are improved, thus. improving the explicit quasiconformal Schwarz lemma and some known estimates for the solutions to the Ramanujan modular equations.展开更多
The mass limit of neutron star has still remained a mystery. The existing Tolman-Oppenheimer-Volkoff (TOV) equation for calculating the limit always gives different values, by introducing different assumptions and hav...The mass limit of neutron star has still remained a mystery. The existing Tolman-Oppenheimer-Volkoff (TOV) equation for calculating the limit always gives different values, by introducing different assumptions and having been predicted like 0.7 Mo, 3.2 Mo, 3.6 Mo, where Mo = 1.98 × 1030 Kg. There is a need of some better technique to adopt other than TOV relation to seek out the value. In this paper, a new relation between the mass of the collapsing star and its average density ρ′ has been derived and used to calculate the limit of neutron star. The conditions in radii between Schwarz Child’s radius and the actual radius of the collapsing star have been introduced to calculate the mass of star above which it will transform into a black hole and below it to a neutron star. A new constant, JN = 8.53707554 × 1039 N-3/2s-3Kg3 has been proposed with which if we introduce the average density of the collapsing neutron star, its mass limit can be calculated very easily. By putting the most possible mass density, which is the minimum required density for a collapsing star to transform into the black hole, it has been found that the mass limit of neutron star is quite higher than it has been assumed. The definition for black hole has also been re-defined on the basis of said radii conditions.展开更多
基金The project supported by National Natural Science Foundation of China under Grant No. 90403019
文摘<正> From the k symmetric action of IIB string in AdS_2×S~2 background given by Zhou,we derive theequations of motion.By using the twisted dual transformation which was introduced by Hou,we construct the flatcurrents,conserving non-local charge with one free parameter,for the superstring in AdS_2×S_2.
基金Supported by National 973 Project of China(2006CB708304)National Natural Science Foundation of China(10771195)
文摘New better estimates, which are given in terms of elementary functions, for the function r →(2/π)(1 -r2)κ(r)κ′(r) + logr appearing in Hubner's sharp upper bound for the Hersch-Pfluger distortion function are obtained. With these estimates, some known bounds for the Hersch-Pfluger distortion function in quasiconformal theory are improved, thus. improving the explicit quasiconformal Schwarz lemma and some known estimates for the solutions to the Ramanujan modular equations.
文摘The mass limit of neutron star has still remained a mystery. The existing Tolman-Oppenheimer-Volkoff (TOV) equation for calculating the limit always gives different values, by introducing different assumptions and having been predicted like 0.7 Mo, 3.2 Mo, 3.6 Mo, where Mo = 1.98 × 1030 Kg. There is a need of some better technique to adopt other than TOV relation to seek out the value. In this paper, a new relation between the mass of the collapsing star and its average density ρ′ has been derived and used to calculate the limit of neutron star. The conditions in radii between Schwarz Child’s radius and the actual radius of the collapsing star have been introduced to calculate the mass of star above which it will transform into a black hole and below it to a neutron star. A new constant, JN = 8.53707554 × 1039 N-3/2s-3Kg3 has been proposed with which if we introduce the average density of the collapsing neutron star, its mass limit can be calculated very easily. By putting the most possible mass density, which is the minimum required density for a collapsing star to transform into the black hole, it has been found that the mass limit of neutron star is quite higher than it has been assumed. The definition for black hole has also been re-defined on the basis of said radii conditions.