It is well known that, in contrast to general relativity, there are two conformally related frames, the jordan frame and the einstein frame, in which the bransdicke. A particular alternative is the brans dicke theory, which has been broadly studied as concerned to kessence type fields in 4d. We show how conformal relativity is related to bransdicke theory and to lowenergyeffective superstring theory. A function of time has been incorporated into the expression of the density of matter to account for the nonconservation of the matter content of the universe. Ageoftheuniverseconstrainedfromtheprimordialnucleosynthesi. In standard einstein theory the spacetime metric tensor, or more. We discuss how inflation, deceleration, cosmic acceleration can result from this solution. Modified bransdicke theory with spacetime anisotropic. Pdf we consider an approach to bransdicke theory of gravity in. Jordanbransdicke, theory based on the 1961 publications of brans. Mach himself never succeeded in stating his ideas in the form of a precisely testable physical theory, and weve seen that to the extent that einsteins hopes and intuition had been formed by machs ideas, he often felt that his own theory of gravity came up short. This theory best suited for a frame work in which the gravitational constant g arise from the structure of the universe. We consider the adm formalism of the bransdicke theory and propose a space time anisotropic extension of the theory by introducing five free parameters.
This is the action of brans dicke theory, which is obviously a subcase of scalartensor theories. We show that dynamical spacetimes in bransdicke theory can violate this. Why isnt bransdicke theory preferable to einsteins general. The bransdicke theorybd is defined by a scalar field. Bransdicke theory was generalized by promoting the constant bransdicke parameter to a function of. In the present work, we study the brans dicke theory in a dimensional reduction context.
These papers substantially duplicate much of the work of jordan and his group. Research article study of antigravity in an model and in brans dicke theory with cosmological constant v. Dec 16, 2016 scalartensor gravitational theories are studied extensively as an alternative to general relativity. In the modern context, the brans dicke theory attempted to rescue the inflationary scenario from some of its problems.
Nov 25, 2016 what every layperson should know about string theory. Pdf conformal relativity versus bransdicke and superstring. More modern versions of scalartensor gravityinclude galileons, generalizedgalileons, and horndeski theory, which are the subject of intensive research 5. Abstract in this short note we report our finding that within the context of alternative version of the bransdicke theory for cj, where u is the bransdicke parameter. However, this theory is almost unexplored in the context of the dimensional reduction in 3d. As we will shortly see, the origins of brans dicke theory is in machs principle according to which the property of inertia of material bodies arises because of their interaction with the matter distributed in the universe. Regular bouncing solutions, energy conditions, and the brans. Brans dicke theory represents a minority viewpoint in physics. Cold neutron star model in brans dicke theory of gravity takuya matsuda. We show that the conformal relativity action is equivalent to the transformed bransdicke action for. Ageoftheuniverseconstrainedfromtheprimordialnucleosynthesis. Generalized sparlingthirring form in the bransdicke theory. Then i have discussed the derivation of the field equation for the bd. Pdf a geometrical approach to bransdicke theory researchgate.
While solving bransdickes field equations for bianchi type v cosmological model, we have used a special law of variation of hubble parameter proposed by berman. At present, both brans dicke theory and general relativity are generally held to be in agreement with observation. For this purpose, we take frw universe model with viscous fluid without potential and bianchi type i universe model with barotropic fluid with and without potential. Initial singularity free quantum cosmology in twodimensional. Brans building upon, among others, the earlier work of pascual jordan. We generalize the bd scalar to complex field with cp violating coupling to curvature and show. Bransdicke theory article about bransdicke theory by the. It is considered by many astronomers to be the most serious alternative to general relativity. Modified bransdicke theory in arbitrary dimensions. Brans building upon, among others, the earlier 1959 work of pascual jordan. Ferreiraa, antonio padillab, constantinos skordisb adepartment of astrophysics, university of oxford, uk.
Z 2 geometry the geometrical meaning of the torsion is clarified. Nov 18, 2014 the bransdicke theory appeared in the beginning of the 1960s as an important alternative to the theory of general relativity gr. Moreover, bransdicke theory arises naturally as the low energy limit of many quantum gravity theories like superstring theory or kaluzaklein theory. A read is counted each time someone views a publication summary such as the title, abstract, and list of authors, clicks on a figure, or views or downloads the fulltext. The theory can also be tested by the observational data coming from cmb and large scale structure 4548.
This is primarily an historical survey of the origins and evolution of only one of a variety of many scalartensor st alternatives to the standard einstein equations of general relativity. Pdf mapping of bransdicke theory to chameleon gravity. There is a long standing debate on the physical equivalence of the formulations in these two different frames. This is the prototype of a scalartensor theory where the nonminimal coupling occurs between the gravitational term and the scalar. Modern physicsbransdicke theory wikibooks, open books for. This paper is devoted to study the accelerated expansion of the universe by exploring the brans dicke parameter in different eras. A unified dark fluid characterised by a linear equation of state is considered as the source of dark energy. The main idea of this theory is to consider the gravitational coupling \g\ as a dynamical quantity, implementing in this way the large number hypothesis formulated by dirac.
Brans dicke is actually the theory that will concern us here. Alam 2 international centre for theoretical physics, trieste, italy. A new mechanism for baryogenesis is proposed in the context of an extended brans dicke bd theory. Secondly, for those aspects of the study that focus on dynamical behavior of the bransdicke theory and its stability in jf, it provides us the possibility to find the corresponding equations in chameleon mechanism in ef which are free from singularity and more easier to discussed then transform them to the bransdick theory in jf. Brans dicke theory has modified upto the self creation cosmology theory of gravity that allows mass creation in the universe. Alternative dynamics in loop quantum brans dicke cosmology shupeng song 1, cong zhangy1,2, and yongge maz 1 department of physics, beijing normal university, beijing 100875, china 2faculty of physics, university of warsaw, pasteura 5, 02093 warsaw, poland april 22, 2020 abstract to inherit more features of full loop quantum brans dicke theory, the euclidean and lorentzian terms of the. The term bransdicke, apparently first introduced by dicke in his 1962 paper. Field equations of brans dicke theory are, 2,, 1 8 11 ij ij ij22 ij i j ij ij ij r gr g t g.
We have studied the generalised bransdicke theory and obtained exact solutions of at. Modi ed gravity and cosmology timothy cliftona, pedro g. Testing scalartensor theories and parametrized postnewtonian. As we will shortly see, the origins of bransdicke theory is in machs principle according to which the property of inertia of material bodies arises because of their interaction with the matter distributed in the universe. I have emphasized on the formalism of brans dicke theory and the need to introduce it. Conformal relativity or the hoylenarlikar theory is invariant with respect to conformal transformations of the metric. What every layperson should know about string theory. Bransdicke is actually the theory that will concern us here. On the gravitational collapse in bransdicke theory of. So it is of little wonder that it is deprecated given the lack of unique observational support for bransdicke theory. Cosmic evolution in generalised bransdicke theory modern.
Entropy free fulltext conformal relativity versus brans. Oct 30, 2015 first, it is shown that regular stationary blackhole solutions not only have constant bransdicke field. Field equations the bransdicke scalartensor theory of gravity requires us to introduce an additional scalar field. Bransdicke theory represents a minority viewpoint in physics. This is the action of bransdicke theory, which is obviously a subcase of scalartensor theories.
Dark energy cosmological models in bransdicke theory of gravity. Karagiannakis 2 department of eoretical physics, aristotle university ofes saloniki, essaloniki, greece. For another, string theory, even in only 10 dimensions, doesnt give you general relativity as your theory of gravity, but rather a 10dimensional brans dicke theory of gravity. Anisotropic dark energy cosmological models are constructed in the frame work of generalised bransdicke theory with a selfinteracting potential. At present, both bransdicke theory and general relativity are generally held to be in agreement with observation. It means a changing gravitational constant may be looked upon as the machian. In the framework of brans dicke theory, a cosmological model regarding the expanding universe has been formulated by considering an interconversion of matter and dark energy. For this we consider a brans dicke scalar field which depends only on the cosmic time. Discrete cosmological models in the bransdicke theory of gravity. Bianchi typev cosmological model with linear equation of. Hydrodynamic calculations of spherical gravitational collapse in the scalartensor theory of gravity takuya matsuda and hidekazu nariai. The goal in this paper is to construct andthen analyze the behavior of a c. In the modern context, the bransdicke theory attempted to rescue the inflationary scenario from some of its problems.
Unified dark fluid in bransdicke theory pdf paperity. Dicke have given an interesting alternative to general theory of relativity based on mechs principle. It is well known that, in contrast to general relativity, there are two conformally related frames, the jordan frame and the einstein frame, in which the brans dicke theory, a prototype of generic scalartensor theory, can be formulated. Initial singularity free quantum cosmology in twodimensional bransdicke theory won tae kim and myung seok yoony department of physics and basic science research institute, sogang university, seoul 121742, korea march 1998 abstract we consider twodimensional bransdicke theory to study the initial singularity problem. A scalartensor theory of gravity containing an arbitrary dicke coupling constant. The brans dicke theory is a wellknown competitor of einsteins more popular theory of general relativity. If two theories are both consistent with the same experimentalobservational data, then we prefer the simpler one. For instance, we can see some problems like the association of the scalar field of the brans dicke theory to kessence fields which models the dark energy, as done in 10. Generalizations of the theory in order to evade this blackhole nohair theorem are presented.
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