Cosmology in scalartensor gravity covers all aspects of cosmology in scalartensor theories of gravity. Ferreiraa, antonio padillab, constantinos skordisb adepartment of astrophysics, university of oxford, uk. In mathematics, tensor calculus, tensor analysis, or ricci calculus is an extension of vector calculus to tensor fields tensors that may vary over a manifold, e. This book provides a clear and concise introduction to the theoretical ideas and developments, exploring scalar. If these equations are anything other than einsteins equations, then we consider it to be a modi ed theory of gravity. This generalization will require some preliminary mathematics. Do solar system experiments constrain scalartensor gravity. Scalartensorvector gravity stvg is a modified theory of gravity developed by john moffat, a researcher at the perimeter institute for theoretical physics in. Scalartensor theories of gravity loyola university new orleans. One of plausible gravity theories is scalartensor theory. Violation of the equivalence principle in scalar tensor theories of gravity by andrias fajarudin diploma in high energy physics 20092010 supervisor. The theory is also often referred to by the acronym mog modified gravity.
Theories of gravitation which include, besides the metric, one or more scalar fields. Of course, the story begins long before my involvement, going. Canonical quantization of anisotropic bianchi i cosmology. The largest part of the relevant literature is devoted to the study of the equivalence between purely metric f rgravity and a speci. A primeron tensor calculus 1 introduction in physics, there is an overwhelming need to formulate the basic laws in a socalled invariant form. In other words, while the weak gravity regime cannot tell apart gr and brans dicke gravity, when higher order terms in the ppn analysis of brans. We applied a generalized scalar vector tensor brans dicke gravity model to study canonical quantization of an anisotropic bianchi i cosmological model. Apr 05, 2015 hi, gravity tensor is explained below. Scalar tensor theories considered as alternative to gr since jordanbransdicke. Neutron stars in general relativity and scalartensor theory of gravity.
Testing scalartensor gravity using space gravitationalwave. Cosmology in scalar tensor gravity covers all aspects of cosmology in scalar tensor theories of gravity. Developed by gregorio riccicurbastro and his student tullio levicivita, it was used by albert einstein to develop his theory of general relativity. Paolo creminelli the abdus salam international centre for theoretical physics strada costiera 11, miramare 34014 trieste, italy to be defended on august 18, 2010. The most general scalartensor theory with secondorder. Einsteins general theory of relativity is a geometrical theory of spacetime.
A functional is a real scalar valued function of one or more vector variables. Core collapse in scalar tensor theory of gravity u. The gravitational tensor or gravitational field tensor, sometimes called the gravitational field strength tensor is an antisymmetric tensor, combining two components of gravitational field the gravitational field strength and the gravitational torsion field into one. Jan 18, 2018 one of the latest is scalar tensor vector gravity stvg theory, also referred as modified gravity mog. Violation of the equivalence principle in scalartensor. Biscalar tensor vector gravity theory bstv is an extension of the tensorvectorscalar gravity theory. Comparing scalartensor gravity and frgravity in the. We study the dynamical description of gravity, the appropriate definition of the scalar field energymomentum tensor, and the relation between them in scalar tensor st theories of gravity. We show that the quantity which one would naively identify as the energymomentum tensor of the scalar field is not appropriate because it is polluted by a part of the dynamical description of gravity. From the very beginning this is not a special relativistic scalar gravity. A scalar theory of gravity had earlier been attempted by g. Qualitative properties of scalartensor theories of gravity abstract. Cosmology in scalartensor gravity covers all aspects of cosmology in scalartensor. Tensor vector scalar gravity teves 1 not to be confused with scalar tensor vector gravity, developed by jacob bekenstein, is a relativistic generalization of mordehai milgroms modified newtonian dynamics mond paradigm 2.
This is a special case of scalartensor gravity characterized only by selfinteraction potential and that, in the newtonian limit, this implies a nonstandard behavior that cannot be compared with the usual ppn limit of general relativity. Published by john moffat in 2005, the weak field limit of this theory predicts an enhanced gravitational attraction on the boundaries of galaxies, where phenomena related to dark matter use to happen and agrees with general relativity inward. For this reason the theory may be called a tensor theory. Pdf reconstruction of a scalartensor theory of gravity in. In this paper, we discuss how the noether symmetry approach. Spontaneous scalarization of black holes in scalartensor gravity. Bransdicke theory is famous scalartensor theory which has a coupling parameter. Cosmology in scalartensor gravity fundamental theories. Ascalartheoryof gravity had earlier been attempted by g. Teves is a relativistic generalization of mordehai milgroms modified newtonian dynamics mond paradigm proposed by jacob bekenstein. Abstract a covariant scalar tensor vector gravity theory is developed which allows the gravitational constant g, a vector field coupling. In chapter 2, a history of the theory of gravity is presented, starting with newtonian gravity and ending with scalartensor gravity. As fg,r gravity,wheregisthegaussbonnettopological invariant and r is the ricci curvature scalar, exhausts all the curvature information that one can construct from the riemann tensor, in the same way, ftg,t contains all the possible information directly related to the torsion tensor. Jan 21, 2000 the present acceleration of the universe strongly indicated by recent observational data can be modeled in the scope of a scalar tensor theory of gravity.
In order to do this however it will be necessary to expand the notion of \ tensor to include a larger class of functions. Noether symmetries in gaussbonnetteleparallel cosmology. Scalartensor theories are simple, interesting examples of modi. The action of horndeski gravity can be written in terms of galileon interactions see 236 and section 2. Today, a distinguishing feature of modern scalar tensor cosmology is that the gravitational coupling is timedependent. Scalartensorvector gravity stvg is a modified theory of gravity developed by john moffat, a researcher at the perimeter institute for theoretical physics in waterloo, ontario. Numerical simulations of stellar collapse in scalar tensor theories of gravity davide gerosa1, ulrich sperhake1,2,3 and christian d ott2,4 1 department of applied mathematics and theoretical physics, centre for. Scalartensor gravity, with the screening mechanisms to avoid the severe constraints of the fifth force in the solar system, can be described with a unified theoretical framework, the socalled. Cosmology in scalartensor gravity covers all aspects of cosmology in scalar tensor. This is a fourvector whose time component is the charge density and the space components are the current density.
Exploring the discrepancies between general relativity and. Numerical simulations of stellar collapse in scalartensor. Considerable progress has been made in this exciting area of physics and this book is the first to provide a critical overview of the research. The scalartensor theory of gravitation the scalartensor theory of gravitation is one of the most popular alternatives to einsteins theory of gravitation. Stars and stellar structure are described in chapter 3. Cosmology in scalartensor gravity fundamental theories of. The technology was initially commercialised for the petroleum exploration industry to assist with defining complex salt. Vector algebra is an essential physics tool for describing vector quantities in a compact fashion. St are fundamental modifications of einsteinhilbert action, rather than phenomenological alterations of friedmann equations or wa. Marine 3d full tensor gravity gradiometry 3d full tensor gradiometry ftg or highprecision moving platform gravity gradiometry measures the full gravity field in all directions. We calculate the bounds which could be placed on scalartensor theories of gravity of the jordan, fierz, brans and dicke type by measurements of gravitational. Recall that the source of electromagnetism is the electric current density. Indeed, the theory he finally arrived at in 1915, general relativity, is a tensor theory, not a scalar theory, with a 2tensor, the metric, as the potential.
The relation between scalartensor theory and f rgravity, and their possible equivalence, has been studied by many authors. Interest in curvature modifications high curvature. Indeed, the papers in this volume are mainly based on the proceedings of the mexican meeting on exact solutions and scalar fields in gravity that was held in honour of heinz dehnen and dietrich kramer. We study the screening mechanism in the most general scalartensor theories that leave gravitational waves unaffected and are thus. Modi ed gravity and cosmology timothy cliftona, pedro g. We generalize the notion of constantroll inflation earlier introduced in general relativity gr and fr gravity to inflationary models in. Yanagida abstract we point out that extended gravity theories, the lagrangian of which is an arbitrary function of scalar.
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