20 research outputs found

    Magnetic Brane of Cubic Quasi-Topological Gravity in the Presence of Maxwell and Born-Infeld Electromagnetic Field

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    The main purpose of the present paper is analyzing magnetic brane solutions of cubic quasi-topological gravity in the presence of a linear electromagnetic Maxwell field and a nonlinear electromagnetic Born-Infeld field. We show that the mentioned magnetic solutions have no curvature singularity and also no horizons, but we observe that there is a conic geometry with a related deficit angle. We obtain the metric function and deficit angle and consider their behavior. We show that the attributes of our solution are dependent on cubic quasi-topological coefficient and the Gauss-Bonnet parameter.Comment: 15 pages and 8 figure

    Reissner-Nordstr\"om Black Holes in Quintic Quasi-topological Gravity

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    This paper presents a study on charged black holes in quintic quasi-topological gravity, where we construct numerical solutions and investigate their thermodynamics and conserved quantities. We verify the first law of thermodynamics and compare our findings with that of Einstein gravity. We examine the physical properties of the solutions, considering anti-de Sitter, de Sitter, and flat solutions. Our analysis shows that anti-de Sitter solutions exhibit thermal stability, whereas de Sitter and flat solutions do not. Finally, we discuss the implications of our results and possible future research directions.Comment: 27 pages, 9 Figure

    Black Holes in (Quartic) Quasitopological Gravity

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    We construct quartic quasitopological gravity, a theory of gravity containing terms quartic in the curvature that yields second order differential equations in the spherically symmetric case. Up to a term proportional to the quartic term in Lovelock gravity we find a unique solution for this quartic case, valid in any dimensionality larger than 4 except 8. This case is the highest degree of curvature coupling for which explicit black hole solutions can be constructed, and we obtain and analyze the various black hole solutions that emerge from the field equations in (n+1)(n+1) dimensions. We discuss the thermodynamics of these black holes and compute their entropy as a function of the horizon radius. We then make some general remarks about KK-th order quasitopological gravity, and point out that the basic structure of the solutions will be the same in any dimensionality for general KK apart from particular cases.Comment: LaTex, 9 figures, 27 pages. A new section on holographic hydrodynamics is added. Introduction and concluding remarks have been revise

    Investigation of the Ds1D_{s1} structure via BcB_c to Ds1l+l−/ννˉD_{s1} l^+l^-/\nu\bar\nu transitions in QCD

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    We investigate the structure of the Ds1(2460,2536)(JP=1+)D_{s1}(2460,2536) (J^P=1^+) mesons via analyzing the semileptonic Bc→Ds1l+l−B_{c}\to D_{s1}l^+l^-, l=τ,μ,el=\tau, \mu, e and Bc→Ds1ννˉB_{c}\to D_{s1}\nu\bar{\nu} transitions in the framework of the three--point QCD sum rules. We consider the Ds1D_{s1} meson in two ways, the pure ∣csˉ>|c\bar{s}> state and then as a mixture of two ∣3P1>|^3P_1> and ∣1P1>|^1P_1> states. Such type rare transitions take place at loop level by electroweak penguin and weak box diagrams in the standard model via the flavor changing neutral current transition of b→sb \to s. The relevant form factors are calculated taking into account the gluon condensate contributions. These form factors are numerically obtained for ∣csˉ>|c\bar s> case and plotted in terms of the unknown mixing angle θs\theta_s, when the Ds1D_{s1} meson are considered as mixture of two ∣3P1>|^3P_1> and ∣1P1>|^1P_1> states. The obtained results for the form factors are used to evaluate the decay rates and branching ratios. Any future experimental measurement on these form factors as well as decay rates and branching fractions and their comparison with the obtained results in the present work can give considerable information about the structure of this meson and the mixing angle θs\theta_s.Comment: 33 Pages, 11 Figures and 5 Table

    Supply and protected different population of Litopenaeus vannamei subadult zero foster (F_0) from difference provinces Iran

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    Nowadays, Litopenaeus vannamei are the most important species of farmed penaeidae shrimp in the world that is rapidly replacing native species in areas aquaculture. Due to demand increase for this species culture, shrimp displacement to different areas may be associated with some potential pathogens transferred to new areas farmed. Therefore, in this study were prepared bi-osecurity conditions for specific disease-free production of L. vannamei. Thereafter, three populations (Molokaei, High health and mix of Molokaei and High health) of the shrimp various reserves were detected base on origin and genetic indexes such as: observed heterozygosity, expected heterozygosity, allele frequency, coefficient inbreeding, genetic differentiation, genetic distance and genetic identity. On the other hand, epidemiological studies indicate non pathogens (viral, bacterial, fungal and parasitic) recognition of different populations selected in the quarantine salon. The bioassay results showed that the average weight and length of the populations of High health and Mix significantly greater than was a population of Molokaei. The shrimp populations were stocked in fiberglass tank (five ton) and were kept separated in the quarantine salon. During maintenance shrimp of populations in the quarantine salon were evaluated living and non-living pathogens with PCR, microbiology and biochemical methods. There is not any pathogens detection from shrimp populations stocking in the quarantine salon, so the shrimps were carried over to pond for broodstock culture of specific pathogenic free

    Supply and protected different population of Litopenaeus vannamei subadult zero foster (F0) from difference provinces Iran

    Get PDF
    Nowadays, Litopenaeus vannamei are the most important species of farmed penaeidae shrimp in the world that is rapidly replacing native species in areas aquaculture. Due to demand increase for this species culture, shrimp displacement to different areas may be associated with some potential pathogens transferred to new areas farmed. Therefore, in this study were prepared bi-osecurity conditions for specific disease-free production of L. vannamei. Thereafter, three populations (Molokaei, High health and mix of Molokaei and High health) of the shrimp various reserves were detected base on origin and genetic indexes such as: observed heterozygosity, expected heterozygosity, allele frequency, coefficient inbreeding, genetic differentiation, genetic distance and genetic identity. On the other hand, epidemiological studies indicate non pathogens (viral, bacterial, fungal and parasitic) recognition of different populations selected in the quarantine salon. The bioassay results showed that the average weight and length of the populations of High health and Mix significantly greater than was a population of Molokaei. The shrimp populations were stocked in fiberglass tank (five ton) and were kept separated in the quarantine salon. During maintenance shrimp of populations in the quarantine salon were evaluated living and non-living pathogens with PCR, microbiology and biochemical methods. There is not any pathogens detection from shrimp populations stocking in the quarantine salon, so the shrimps were carried over to pond for broodstock culture of specific pathogenic free

    Thermodynamics of static solutions in ( n

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