By restricting the common replacement axiom schema of ZF to ∑~M-formulae,Professor Zhang Jinwen constructed a series of subsystems of Zennelo-Frankel set theory ZF and he called them ZF^M.Zhao Xi shun show that the c...By restricting the common replacement axiom schema of ZF to ∑~M-formulae,Professor Zhang Jinwen constructed a series of subsystems of Zennelo-Frankel set theory ZF and he called them ZF^M.Zhao Xi shun show that the consistency of ZF^M can be deducted from ZF.Professor Zhang Jinwen raised the question whether the consistency of ZF^M can be deducted from ZF^(M+m(M)) for some m(n)≥1.In this paper,we get a positive solution to Professor Zhang's problem.Moreover,we show that the consistency of ZF^M can be deducted from ZF^(M+3).展开更多
Using a navigation process with the datum(F,V),in which F is a Finsler metric and the smooth tangent vector field V satisfies F(−V(x))>1 everywhere,a Lorentz Finsler metric F˜can be induced.Isoparametric functions ...Using a navigation process with the datum(F,V),in which F is a Finsler metric and the smooth tangent vector field V satisfies F(−V(x))>1 everywhere,a Lorentz Finsler metric F˜can be induced.Isoparametric functions and isoparametric hypersurfaces with or without involving a smooth measure can be defined for F˜.When the vector field V in the navigation datum is homothetic,we prove the local correspondences between isoparametric functions and isoparametric hypersurfaces before and after this navigation process.Using these correspondences,we provide some examples of isoparametric functions and isoparametric hypersurfaces on a Funk space of Lorentz Randers type.展开更多
文摘By restricting the common replacement axiom schema of ZF to ∑~M-formulae,Professor Zhang Jinwen constructed a series of subsystems of Zennelo-Frankel set theory ZF and he called them ZF^M.Zhao Xi shun show that the consistency of ZF^M can be deducted from ZF.Professor Zhang Jinwen raised the question whether the consistency of ZF^M can be deducted from ZF^(M+m(M)) for some m(n)≥1.In this paper,we get a positive solution to Professor Zhang's problem.Moreover,we show that the consistency of ZF^M can be deducted from ZF^(M+3).
基金Supported by Beijing Natural Science Foundation(Grant No.1222003)National Natural Science Foundation of China(Grant Nos.12131012,11821101 and 12001007)Natural Science Foundation of Anhui province(Grant Nos.2008085QA03 and 1908085QA03)。
文摘Using a navigation process with the datum(F,V),in which F is a Finsler metric and the smooth tangent vector field V satisfies F(−V(x))>1 everywhere,a Lorentz Finsler metric F˜can be induced.Isoparametric functions and isoparametric hypersurfaces with or without involving a smooth measure can be defined for F˜.When the vector field V in the navigation datum is homothetic,we prove the local correspondences between isoparametric functions and isoparametric hypersurfaces before and after this navigation process.Using these correspondences,we provide some examples of isoparametric functions and isoparametric hypersurfaces on a Funk space of Lorentz Randers type.
