Since Kostelecky et al [Phys Rev Lett 100, 111102 (2008)], have shown that there is an intimate connection between spacetime with torsion and the possibility of constraining it to Lorentz violation, a renewed interest...Since Kostelecky et al [Phys Rev Lett 100, 111102 (2008)], have shown that there is an intimate connection between spacetime with torsion and the possibility of constraining it to Lorentz violation, a renewed interest in torsion theories of gravity has arised. In this paper, minimal coupling between photons on a torsioned background is shown to allow us to obtain the galactic magnetic field strength μG without dynamo amplification. This agrees with recent results by Jimenez and Maroto (2011) for spiral galaxies, with galactic magnetic field constraints from Dark matter without dy- namo amplification. The approach discussed here allow us to get rid of the unpleasant photon mass by simply consider- ing the Lagrangean cut off for second order torsion terms. Therefore though the gauge and Lorentz symmetries are bro- ken here one does not have to deal with photon masses.展开更多
For a hereditary torsion theory τ, this paper mainly discuss properties of A-τ-injective modules, where A is a fixed left R-module. It is proved that if M is an A-τ-injective, B is a submodule of A, then 1） M is A...For a hereditary torsion theory τ, this paper mainly discuss properties of A-τ-injective modules, where A is a fixed left R-module. It is proved that if M is an A-τ-injective, B is a submodule of A, then 1） M is A/B-τ-injective; 2） M is B-τ-injective when B is τ-dense in A. Furthermore, we show that if A1,A2,... An, are relatively injective modules, then A1 A2 ... An is self-τ-injective if and only if A1 is self-τ-injective for each i.展开更多
Let τ be a torsion theory on R-rood and M be a left R-mod. In this paper the τ-cotorsionfree radical Cτ（M） of M is studied. When τ is stable, the construction and the supplementing radical of Cτ （M） are obtai...Let τ be a torsion theory on R-rood and M be a left R-mod. In this paper the τ-cotorsionfree radical Cτ（M） of M is studied. When τ is stable, the construction and the supplementing radical of Cτ （M） are obtained.展开更多
In the paper, we define（inco） project modules of relatively hereditary torsion theory τ by intersection complement of module and study their properties; secondly, we define the（inco） τ-semisimple ring by（inco）...In the paper, we define（inco） project modules of relatively hereditary torsion theory τ by intersection complement of module and study their properties; secondly, we define the（inco） τ-semisimple ring by（inco） τ-projective module and study their properties. When r is a trivial torsion theory on R-rood, we prove that R is a semisimple ring if and only if R is a（inco） semisimple ring and satisfies（inco） condition.展开更多
Let R be a ring with identity, x be a central element of R which is neither a unit nor azero divisor. S=R/xR is the quotient ring of R and R → R/xR is the natural map.R-Mod(resp. S-Mod) denotes the category of unit...Let R be a ring with identity, x be a central element of R which is neither a unit nor azero divisor. S=R/xR is the quotient ring of R and R → R/xR is the natural map.R-Mod(resp. S-Mod) denotes the category of unital left R-modules(resp. S-modules). In.this paper, relationships betwee torsion theories on R-Mod and torsion theories on S-Mod areinvestigated. Properties of the functor ExtR(N, -) are given. Properties of the localizationfunctor Qσare also investigated.展开更多
The generalized Lagrangians of matter field and gravitational fields are specified and their invariances under (ε^(mn), ξ~μ) transformations in the space-time with torsion are studied. The possible forms of couplin...The generalized Lagrangians of matter field and gravitational fields are specified and their invariances under (ε^(mn), ξ~μ) transformations in the space-time with torsion are studied. The possible forms of coupling between gravitational fields and matter field as well as the possible types of gravitational Lagrangian are derived. Some physical quantities are introduced and several interesting conclusions are discussed.展开更多
Some properties of and relations between several （big） lattices of module classes are used in this paper to obtain information about the ring over which modules are taken. The authors reach characterizations of triv...Some properties of and relations between several （big） lattices of module classes are used in this paper to obtain information about the ring over which modules are taken. The authors reach characterizations of trivial rings, semisimple rings and certain rings over which every torsion theory is hereditary.展开更多
In this paper, after discussing some properties of quotient contexts of a Morira context, well show that if DR is a perfect Gopriel topology, the quotient context of (P, Q), where (P, Q) as all MC between rings R and...In this paper, after discussing some properties of quotient contexts of a Morira context, well show that if DR is a perfect Gopriel topology, the quotient context of (P, Q), where (P, Q) as all MC between rings R and S is the quotient context of (P, Q), is isomorphic to a quotient context of (P, Q).展开更多
基金Financial support from CNPq.and University of State of Rio de Janeiro(UERJ)
文摘Since Kostelecky et al [Phys Rev Lett 100, 111102 (2008)], have shown that there is an intimate connection between spacetime with torsion and the possibility of constraining it to Lorentz violation, a renewed interest in torsion theories of gravity has arised. In this paper, minimal coupling between photons on a torsioned background is shown to allow us to obtain the galactic magnetic field strength μG without dynamo amplification. This agrees with recent results by Jimenez and Maroto (2011) for spiral galaxies, with galactic magnetic field constraints from Dark matter without dy- namo amplification. The approach discussed here allow us to get rid of the unpleasant photon mass by simply consider- ing the Lagrangean cut off for second order torsion terms. Therefore though the gauge and Lorentz symmetries are bro- ken here one does not have to deal with photon masses.
基金Supported by the National Natural Science Foundation of China(10571026)Supported by the Research Foundation of the Education Committee of Anhui Province(2006kj050c)Supported by the Doctoral Foundation of Anhui Normal University
文摘For a hereditary torsion theory τ, this paper mainly discuss properties of A-τ-injective modules, where A is a fixed left R-module. It is proved that if M is an A-τ-injective, B is a submodule of A, then 1） M is A/B-τ-injective; 2） M is B-τ-injective when B is τ-dense in A. Furthermore, we show that if A1,A2,... An, are relatively injective modules, then A1 A2 ... An is self-τ-injective if and only if A1 is self-τ-injective for each i.
文摘Let τ be a torsion theory on R-rood and M be a left R-mod. In this paper the τ-cotorsionfree radical Cτ（M） of M is studied. When τ is stable, the construction and the supplementing radical of Cτ （M） are obtained.
基金Supported by the Science and Technology Develop Foundation of Jilin Science and Technology Department(20040506-3)
文摘In the paper, we define（inco） project modules of relatively hereditary torsion theory τ by intersection complement of module and study their properties; secondly, we define the（inco） τ-semisimple ring by（inco） τ-projective module and study their properties. When r is a trivial torsion theory on R-rood, we prove that R is a semisimple ring if and only if R is a（inco） semisimple ring and satisfies（inco） condition.
文摘Let R be a ring with identity, x be a central element of R which is neither a unit nor azero divisor. S=R/xR is the quotient ring of R and R → R/xR is the natural map.R-Mod(resp. S-Mod) denotes the category of unital left R-modules(resp. S-modules). In.this paper, relationships betwee torsion theories on R-Mod and torsion theories on S-Mod areinvestigated. Properties of the functor ExtR(N, -) are given. Properties of the localizationfunctor Qσare also investigated.
基金Project supported by the National Natural Science Foundation of China.
文摘The generalized Lagrangians of matter field and gravitational fields are specified and their invariances under (ε^(mn), ξ~μ) transformations in the space-time with torsion are studied. The possible forms of coupling between gravitational fields and matter field as well as the possible types of gravitational Lagrangian are derived. Some physical quantities are introduced and several interesting conclusions are discussed.
文摘Some properties of and relations between several （big） lattices of module classes are used in this paper to obtain information about the ring over which modules are taken. The authors reach characterizations of trivial rings, semisimple rings and certain rings over which every torsion theory is hereditary.
文摘In this paper, after discussing some properties of quotient contexts of a Morira context, well show that if DR is a perfect Gopriel topology, the quotient context of (P, Q), where (P, Q) as all MC between rings R and S is the quotient context of (P, Q), is isomorphic to a quotient context of (P, Q).
