31,860 research outputs found
Quasi-homologous spherically symmetric branes and their symmetry breaking
We revisit the dynamical system based approach of spherically symmetric
vacuum braneworlds, pointing out and studying the existence of a transcritical
bifurcation as the dark pressure parameter changes its sign, we analyze some
consequences of not discard the brane cosmological constant. For instance, it
is noteworthy that the existence of an isothermal state equation between the
dark fluid parameters cannot be obtained via the requirement of a
quasi-homologous symmetry of the vacuum.Comment: 20 pages, 12 figures. To appear in EPJ
Solution for a local straight cosmic string in the braneworld gravity
In this work we deal with the spacetime shaped by a straight cosmic string,
emerging from local gauge theories, in the braneworld gravity context. We
search for physical consequences of string features due to the modified
gravitational scenario encoded in the projected gravitational equations. It is
shown that cosmic strings in braneworld gravity may present significant
differences when compared to the general relativity predictions since its
linear density is modified and the deficit angle produced by the cosmic string
is attenuated. Furthermore, the existence of cosmic strings in that scenario
requires a strong restriction to the braneworld tension: , in Planck units.Comment: 7 pages, 3 figure
Static Domain Wall in the Braneworld gravity
In this paper we consider a static domain wall inside a 3-brane. Differently
of the standard achievement obtained in General Relativity, the analysis
performed here gives a consistency condition for the existence of static domain
walls in a braneworld gravitational scenario. It is also shown the behavior of
the domain wall gravitational field in the newtonian limit.Comment: 11 pages, no figures, accepted for publication in EPJ
Efeito de antÃdotos na atividade das cloroacetanilidas sobre as plantas de sorgo (Sorghum bicolor (L.) Moench.
Foram conduzidos dois experimentos, no ano agricola 1983/84, objetivando estudar a eficiencia dos antidotos CGA 92194 CGA 43089 sobre a tolerancia dos cultivares de sorgo BR 300 (granifero) e BR 501 (sacarino) as cloroacetanilidas e ao atrazine, bem como os respectivos efeitos desses herbicidas sobre a s plantas daninhas. O solo do local escolhido para a instalacao dos ensaios, em 1983/84, foi um Latossolo Vermelho-Escuro, fase cerrado, com textura argilosa e materia organica entre 2,57 e 2,90%. O delineamento experimental foi em blocos ao acaso, em esquema fatorial completo, com quatro repeticoes. Os tratamentos foram: atrazine a 1,5 kg/ha, aplicado isoladamente e em mistura com metolachlor, alachlor, acetochlor e propachlor, com e sem antidoto, mais uma testemunha, sem herbicida, capinada e sem capina. Os antidotos foram aplicados na forma de tratamento de sementes. As caracteristicas avaliadas foram: stand, inicial e final, altura de plantas, numero de paniculas, peso de paniculas, producao de graos, densidade de plantas daninhas e peso da materia seca da parte aerea aos 34 e 64 dias apos a aplicacao dos produtos. Para o sorgo sacarino, alem dessas caracteristicas, avaliaram-se ainda o peso da massa verde total da parte aerea, o peso total dos colmos despalhados, o diametro do colmo despalhado, a percentagem de caldo extraido, acucares redutores, acucares redutores totais, sacarose total sacarose e brix, determinados segundo metodo proprio do CNPMS, Sete Lagoas, MG
Soil nutrient amendment with leaves of varying quality.
Study on the impact of nitrogen and phosphorus fertilization combined with litter amendment on the microbial biomass ofa xanthic Ferralso. (0cm-5cm and 10cm-20cm). First peliminary results after 18 days of incubation showed that soil amended with P tended to have higher microbial C than soils fertilized with N or the control. This result indicates that nitrogen is probably not limiting microbial biomass growth the most , but rather P.bitstream/item/181049/1/ID-2600-2-58.pd
Spin-1 Particles with Light-Front Approach
For the vector sector, i.e, mesons with spin-1, the electromagnetic form
factors and anothers observables are calculated with the light-front approach.
However, the light-front quantum field theory have some problems, for example,
the rotational symmetry breaking. We solve that problem added the zero modes
contribuition to the matrix elements of the electromagnetic current, besides
the valence contribuition. We found that among the four independent matrix
elements of the plus component in the light-front helicity basis only the one carries zero mode contributions.Comment: 5 pages. 3 Figures, use latex and EPJ styl
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