Boosted further by the discovery of dbranes as fundamental objects in string theories, this. General relativity and quantum cosmology authorstitles new. Ferreiraa, antonio padillab, constantinos skordisb adepartment of astrophysics, university of oxford, uk. Brane cosmology refers to several theories in particle physics and cosmology related to string theory, superstring theory and mtheory brane and bulk. The canonical quantization of the modified geodetic brane cosmology which is implemented from the reggeteitelboim model and the trace of the extrinsic curvature of the brane trajectory, \k\, is developed. Within a friedmannrobertsonwalker metric, we obtain a generalized. Modified friedmann equations on the brane from entropic force modified friedmann equations on the brane from entropic force sheykhi, ahmad 20110804 00. Brane world scenarios and the cosmological constant request pdf. The modified geodetic brane gravity mgbg 1 is an effective theory consisting of the reggeteitelboim model rt, also named geodetic brane gravity gbg 2 6 plus a geometric linear k. At the quantum level, the road is open for canonical andor functional integral quantization.
Cosmology and stability in scalartensor bigravity kb, kokusho, nojiri and shirai, arxiv. The canonical quantization of the modified geodetic brane cosmology which is implemented from the reggeteitelboim model and the trace of the extrinsic curvature of the brane trajectory, is developed. The idea of modifying gravity on cosmological scales has really taken off over the past decade. It is nearly impossible to avoid discussing modified gravity without resorting to. Gaussbonnet braneworld cosmology with modified induced. A dark energy model of the hybrid symmetron leading to the spontaneous symmetry breaking in the universe kb, gannouji, kamijo, nojiri and sami, jcap 7, 017 20. Dark dbrane cosmology iopscience institute of physics. Although the mathematical formalism is essential, some of the main ideas underlying the formalism are simple and it helps to have an intuitive and qualitative notion of these ideas. To investigate cosmology described by solution, we rewrite the original friedmann equation in the following form in order to create a general relativistic description of our model. Modified hamiltonian formalism for reggeteitelboim cosmology. Modified geodetic brane cosmology a simple but interesting brane geometry is provided by a spherical configuration. Abstract the modified geodetic brane cosmology mgbc is tested with observational data.
The ostrogradski approach for the hamiltonian formalism of higher derivative theory is not satisfactory because the lagrangian cannot be viewed as a function on the tangent bundle to coordinate manifold. Pdf modified geodetic brane cosmology researchgate. Brane models provide a somewhat exotic, yet interesting extension of our parameter space for gravitational theories. In the geodetic brane gravity action we accommodate the correction term through a linear term in the extrinsic curvature swept out by the brane. The modi ed geodetic brane cosmology mgbc is tested with observational data. Traditionally, cosmology was taught, as it was to me, as the tail end of a general relativity course, with a derivation ofthe metric for an expanding universe and a few solutions. In this model, the geodesic equation remains structurally as in eq. Modified holographic dark energy in dgp brane world. Pdf modified geodetic brane cosmology efrain rojas. A 5d realization of the horavawitten theory and the corresponding braneworld cosmology is given in. Based on this theory we investigate the kaluzaklein two brane worlds cosmology at low energy, in both the static and the nonstatic internal dimensions. In this way, quantum gravity can begin to be subject to testing by astrophysical and cosmological observations. Research article gaussbonnet braneworld cosmology with.
Modified gravity and cosmology, physics reports 10. Quantum modified reggeteitelboim cosmology nasaads. Unfortunately, the national bureau of standards has not gotten around to establishing a standard notation for cosmological equations. The effectiveness of cosmography lies in the fact that it allows, based on the observations, to perform a rigid selection of models that do not contradict the cosmological principle. Basic assumptions made in the construction of cosmological models. Research article gaussbonnet braneworld cosmology with modified induced gravity on the brane kouroshnozari, 1 faezekiani, 2 andnargesrashidi 2 center for excellence in astronomy and astrophysics ceaairiaam,p. Kaluzaklein twobraneworlds cosmology at low energy. The canonical quantization of the modified geodetic brane cosmology which is implemented from the reggeteitelboim model and the trace of the extrinsic curvature of the brane trajectory, k, is. Finally in the last section we will summarize the basic ideas and results of brane cosmology. Cosmology is the study of the largescale structure and.
It is obvious that the additional source term on the brane will modify the. Comparing this relation with the friedmann equation in gr we obtain an effective energy density which can be rewritten as follows. We study the resulting geodetic type equation of motion. Using a relativistic geometric approach, it focuses on. This can be seen from the modification of the gravitational potential. International publisher science, technology, medicine. Brane world scenarios offer a way of ensuring that a poincare invariant. This article, which is intended as a brief introduction to the series of. The mgbc is derived from the geodetic brane gravity action corrected by the extrinsic curvature of the braneworld. In this paper, we have used an alternative approach which leads directly to the lagrangian which, being a function on the tangent manifold, gives correct equation of. Request pdf brane world scenarios and the cosmological constant brane world. In this work we have considered the dgp model with a brane scalar field. Box, maragha, iran department of physics, faculty of basic sciences, university of mazandaran, p. Within a friedmannrobertsonwalker metric, we obtain a generalized friedmann equation describing the associated cosmological evolution.
Such a course fails to capture the flavour of modem cosmology. A new hamiltonian formulation of the minisuperspace cosmology following from the geodetic brane gravity model introduced by regge and teitelboim is presented. This book surveys key developments and open issues for graduate students and researchers. This cited by count includes citations to the following articles in scholar. Modified geodetic brane cosmology abstract classical and quantum gravity. Applying this modified entropyarea relation to brane cosmology, we derive the modified cosmological equations governing the evolution of the universe on the brane. The model is considered in the framework of higher derivative theories which facilitates hamiltonian formulation. Modi ed gravity and cosmology timothy cliftona, pedro g. Quantum modified reggeteitelboim cosmology springerlink. In this letter, the cosmological dynamics of a modified holographic dark energy which is derived from the uvir duality by considering the black hole mass in higher dimensions as uv cutoff, is investigated in dvaligabadadzeporrati dgp brane world model. Quantum gravity of a brane like universe is formulated, and its einstein limit is approached. The first term in 27 is called geodetic precession, and is caused by the unit curvature of the space. The normal gravity formula and the polar flattening. It seems that every cosmology book has its own notation.
In the geodetic brane gravity action, we accommodate the correction term through a linear term in the extrinsic curvature swept out by the brane. Advances in modern cosmology have prompted renewed interest in the intersections between religion, theology and cosmology. The canonical quantization of the modified geodetic brane cosmology which is implemented from the reggeteitelboim model and the trace of the extrinsic curvature of the brane trajectory, k, is developed. The analysis is done using the equivalent firstorder. The wellknown area relation of the black hole entropy can be modified from the inclusion of quantum effects, motivated from the loop quantum gravity. Observations in cosmology how the models really work. It explains the significance and impact of geodetic concepts using general theory approach. The hamiltonjacobi formalism for a geodetic brane like universe. Applying this modified entropyarea relation to brane cosmology. As a secondorder derivative model, on the grounds of the ostrogradski hamiltonian method and the diracs scheme for constrained systems, we find. Modified gravity inspired dgp brane cosmology sciencedirect. The ones marked may be different from the article in the profile. The scalar field was motivated and inspired by a desire to study the effects of modified gravity, represented by a term like r. We explore the cosmological implications provided by the geodetic brane gravity action corrected by an extrinsic curvature brane term, describing a codimension1 brane embedded in a 5d fixed minkowski spacetime.
However, quite generally, braneworld models which modify gravity at large. Relativisticcosmology cosmology has been transformed by dramatic progress in highprecision observations and theoretical modelling. Thomson department of geodesy and geomatics engineering university of new brunswick p. Brane world cosmology 3 idea by antoniadis, proposed an interesting, but simple model, considering a. Stationary rotating strings can be viewed as geodesic motions in. My main motivation was to make the notation as clear as possible for the cosmological novice. The central idea is that the visible, threedimensional universe is restricted to a brane inside a higherdimensional space, called. Phantom solution in a nonlinear israelstewart theory.
The recent observational data in cosmology seem to indicate that the universe. An introduction to modern cosmology university of belgrade. Modified friedmann equations on the brane from entropic. Pdf modified geodetic brane cosmology efrain coronel. We computed the values of flattening of the equipotential ellipsoid of the earths field and of coefficients of the normal gravity, according to the earths parameters adopted by the international union of geodesy and geophysics at its general assembly of 1967 taking into account the mass of atmosphere and using the closed formulae of the pizzetti somigliana.
Read modified gravity and cosmology, physics reports on deepdyve, the largest online rental service for scholarly research with thousands of academic publications available at your fingertips. The models turn out to be remarkably successful, but we need to ask how secure these foundations are. The density parameter coming from this additional term produces an accelerated expansion of geometrical origin. Reggeteitelboim embedding of arnowittdesermisner formalism, parametrized by the coordinates y a t,x i, is governed by some. Specializing these constraints to a particular modified theory, we find that consistency with general relativity places the most stringent constraint on gravitational parity violation to date, surpassing all other previously reported bounds by seven orders of magnitude.