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Abdel-Rahman, A. M. M.

doi:10.1023/a:1013151416526

Cited by 14 publications

(15 citation statements)

References 14 publications

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“…Based on these observational evidences, there have been some recently studies of the various cosmic eras in the framework of Rastall gravity [18][19][20][21][22]. Other interesting a e-mail: cordac.galilei@gmail.com issues are that Rastall gravity seems to do not suffer from the entropy and age problems of standard cosmology [23] and is consistent with the gravitational lensing phenomena [24,25]. Further interesting works on Rastall gravity are given by [26][27][28][29][30] and references within.…”

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confidence: 99%

Einstein and Rastall theories of gravitation in comparison

Darabi

Moradpour

Licata³

et al. 2018

Eur. Phys. J. C

161

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We profit by a recent paper of Visser claiming that Rastall gravity is equivalent to Einstein gravity to compare the two gravitational theories in a general way. Our conclusions are different from Visser's ones. We indeed argue that these two theories are not equivalent. In fact, Rastall theory of gravity is an "open" theory when compared to Einstein general theory of relativity. Thus, it is ready to accept the challenges of observational cosmology and quantum gravity.The framework of extended theories of gravity [1][2][3][4][5] is today considered an useful and popular approach to attempt to solve the important problems of the standard model of cosmology like Dark Energy [6,7] and Dark Matter [8,9]. A key point is that all of the potential alternatives to Einstein's general theory of relativity (GTR) must be viable. This implies that alternative theories must be in agreement with the Einstein's equivalence principle, which has today a strong, unchallengeable empirical evidence [2]. The fundamental consequence is that the alternatives to Einstein gravity must be metric theories [2]. Another important point is that such alternatives must pass the solar system tests. Hence, deviations from the standard GTR must be weak [1,2].Within the framework of extended gravity, one finds the theory proposed by Rastall in 1972 [10], which recently obtained a renewed interest in the literature [11][12][13][14]. This interest is due to some good behavior of the Rastall theory. In fact, on one hand it seems in good agreement with observational data on the Universe age and on the Hubble parameter [15]. On the other hand it may, in principle, provide an alternative description for the matter dominated era with respect to the GTR [16]. Observational data from the helium nucleosynthesis seem also in agreement with Rastall gravity [17]. Based on these observational evidences, there have been some recently studies of the various cosmic eras in the framework of Rastall gravity [18][19][20][21][22]. Other interesting a e-mail: cordac.galilei@gmail.com issues are that Rastall gravity seems to do not suffer from the entropy and age problems of standard cosmology [23] and is consistent with the gravitational lensing phenomena [24,25]. Further interesting works on Rastall gravity are given by [26][27][28][29][30] and references within.Differently from Einstein gravity, Rastall gravity considers a non-divergence-free energy-momentum . A different, but similar theory is the so called Curvature-matter theory of gravity [31][32][33][34][35]. In this theory the matter and geometry are coupled to each other in a non-minimal way [31][32][33][34][35]. Then, the standard energy-momentum conservation law does not work in this case too [31][32][33][34][35].In a recent paper [36], Visser claimed that Rastall gravity is equivalent to Einstein gravity. In this letter, we argue that these two theories are not equivalent instead. Let us see the key points of our interpretation.Rastall did not define a new energy-momentum tensor (EMT) in his origina...

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confidence: 99%

Einstein and Rastall theories of gravitation in comparison

Darabi

Moradpour

Licata³

et al. 2018

Eur. Phys. J. C

161

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“…In order to ultimately conclude that the GTR is the definitive theory of gravity, one must prove that the oscillations of the interferometer's mirror are in fact governed by eqs. (35). Otherwise, if one proves that the oscillations of the interferometer's mirror are in fact governed by eqs.…”

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confidence: 96%

The commutator algebra of covariant derivative as general framework for extended gravity. The Rastall theory case and the role of the torsion

Licata¹,

Moradpour

Corda

2017

Int. J. Geom. Methods Mod. Phys.

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In this short review, we discuss the approach of the commutator algebra of covariant derivative to analyse the gravitational theories, starting from the standard Einstein's general theory of relativity and focusing on the Rastall theory. After that, we discuss the important role of the torsion in this mathematical framework.In the Appendix of the paper we analyse the importance of the nascent gravitational wave astronomy as a tool to discriminate among the general theory of relativity and alternative theories of gravity.

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“…This can be accomplished by inverse electron demand, pericyclic (4π‐2π) cycloaddition. Hence many heterodienes and heterodienophiles have been used for this purpose . Formation of two products i. e. a heterodienic adduct (dihydropyran) or dienic adduct (cyclohexenes) takes place when (4π‐2π) cycloaddition reaction occurs between a diene and α,β‐unsaturated carbonyl compounds.…”

Section: Cycloaddition Reactions As a Main Tool For Developing Sustaimentioning

confidence: 99%

Aluminum‐Based Catalysts for Cycloaddition Reactions: Moving One Step Ahead in Sustainability

Dogra

Gupta

2019

ChemistrySelect

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A large variety of dienes and alkenes can be derived from plants and used further for the production of fine chemicals or biologically active compounds. Herein, we have identified such dienes/alkenes, as well as their synthetic analogues, and presented a strategy for their conversion by atom-economical cycloaddition reactions. The catalyst used for these conversions is derived from abundantly-available aluminum metal in earth's crust, which has low toxicity, easy availability and low price in comparison to the transition metals. Astonishingly, the applications of aluminum-based catalysts are underdeveloped in comparison to the d-block metal analogues. Therefore, this review summarizes the developments in the field of cycloaddition reactions by using aluminum-based catalysts, a pathway that can be pursued for developing "Sustainable Processes". . Zeolite (81) catalysed cycloaddition of isoprene with dienes 38 (a-d) Scheme 22. Synthesis of TCPD by oligomerization of DCPD and DCPD oligomer isomerisationReviews

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Cited by 14 publications

References 14 publications

Einstein and Rastall theories of gravitation in comparison

Einstein and Rastall theories of gravitation in comparison

The commutator algebra of covariant derivative as general framework for extended gravity. The Rastall theory case and the role of the torsion

Aluminum‐Based Catalysts for Cycloaddition Reactions: Moving One Step Ahead in Sustainability

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