Cosmic topology

Lachièze‐Rey, M.; Luminet, Jean‐Pierre

doi:10.1016/0370-1573(94)00085-h

Cited by 404 publications

(495 citation statements)

References 82 publications

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“…The latter means that the points x + kL, y + mL, z + nL, where k, m, n are integers and both negative and positive values, are identified with a characteristic identification scale L. As was shown in [177] the Casimir energy density in such a model can drive the inflation process. A number of multi-connected cosmological models have been investigated in the literature (see the review [178]). If the identification scale is smaller than the horizon, some observational effects of non-trivial topology are possible.…”

Section: Cosmological Modelsmentioning

confidence: 99%

New developments in the Casimir effect

2001

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We provide a review of both new experimental and theoretical developments in the Casimir effect. The Casimir effect results from the alteration by the boundaries of the zero-point electromagnetic energy. Unique to the Casimir force is its strong dependence on shape, switching from attractive to repulsive as function of the size, geometry and topology of the boundary. Thus the Casimir force is a direct manifestation of the boundary dependence of quantum vacuum. We discuss in depth the general structure of the infinities in the field theory which are removed by a combination of zeta-functional regularization and heat kernel expansion. Different representations for the regularized vacuum energy are given. The Casimir energies and forces in a number of configurations of interest to applications are calculated. We stress the development of the Casimir force for real media including effects of nonzero temperature, finite conductivity of the boundary metal and surface roughness. Also the combined effect of these important factors is investigated in detail on the basis of condensed matter physics and quantum field theory at nonzero temperature. The experiments on measuring the Casimir force are also reviewed, starting first with the older measurements and finishing with a detailed presentation of modern precision experiments. The latter are accurately compared with the theoretical results for real media. At the end of the review we provide the most recent constraints on the corrections to Newtonian gravitational law and other hypothetical long-range interactions at submillimeter range obtained from the Casimir force measurements.

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Section: Cosmological Modelsmentioning

confidence: 99%

New developments in the Casimir effect

2001

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“…On the other hand, flat universes with boundaries or edges are not desired mathematically, and thus, they are excluded from consideration. Although there are some finite compact universe models without boundaries, the torus universe is the one which explains an overall flat and a finite universe [16].…”

Section: Jhep01(2018)017mentioning

confidence: 99%

Lagrange multiplier and Wess-Zumino variable as extra dimensions in the torus universe

Nejad

Dehghani

Monemzadeh

2018

J. High Energ. Phys.

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Abstract:We study the effect of the simplest geometry which is imposed via the topology of the universe by gauging non-relativistic particle model on torus and 3-torus with the help of symplectic formalism of constrained systems. Also, we obtain generators of gauge transformations for gauged models. Extracting corresponding Poisson structure of existed constraints, we show the effect of the shape of the universe on canonical structure of phase-spaces of models and suggest some phenomenology to prove the topology of the universe and probable non-commutative structure of the space. In addition, we show that the number of extra dimensions in the phase-spaces of gauged embedded models are exactly two. Moreover, in classical form, we talk over modification of Newton's second law in order to study the origin of the terms appeared in the gauged theory.

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“…In fact, it has been known for more than 30 years [17,18] that, to one-loop order, there are no unstable modes in de Sitter background provided the parameters of the model obey certain inequalities, which our present model satisfies. 31 To our knowledge, this has been most thoroughly investigated to by date by Ashtekar, Bonga, and Kesevan [38][39][40][41] who emphasize several distinct features of de Sitter space. No matter how small the cosmological constant, there are "no asymptotic Hilbert spaces in dynamical situations of semi-classical gravity" [39].…”

Section: Jhep05(2016)185mentioning

confidence: 99%

“…Although the physical interpretation of a "particle" is frame-dependent, each piece of the experimental apparatus singles out a special reference frame. 33 Exactly how this is to be generalized to de Sitter space with strong curvature has not been precisely 31 There are however several zero modes to be dealt with. This is reviewed in ref.…”

Section: Jhep05(2016)185mentioning

confidence: 99%

Induced gravity II: grand unification

Einhorn

Jones

2016

J. High Energ. Phys.

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As an illustration of a renormalizable, asymptotically-free model of induced gravity, we consider an SO(10) gauge theory interacting with a real scalar multiplet in the adjoint representation. We show that dimensional transmutation can occur, spontaneously breaking SO(10) to SU(5)⊗U(1), while inducing the Planck mass and a positive cosmological constant, all proportional to the same scale v. All mass ratios are functions of the values of coupling constants at that scale. Below this scale (at which the Big Bang may occur), the model takes the usual form of Einstein-Hilbert gravity in de Sitter space plus calculable corrections. We show that there exist regions of parameter space in which the breaking results in a local minimum of the effective action giving a positive dilaton (mass) 2 from two-loop corrections associated with the conformal anomaly. Furthermore, unlike the singlet case we considered previously, some minima lie within the basin of attraction of the ultraviolet fixed point. Moreover, the asymptotic behavior of the coupling constants also lie within the range of convergence of the Euclidean path integral, so there is hope that there will be candidates for sensible vacua. Although open questions remain concerning unitarity of all such renormalizable models of gravity, it is not obvious that, in curved backgrounds such as those considered here, unitarity is violated. In any case, any violation that may remain will be suppressed by inverse powers of the reduced Planck mass.

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Cosmic topology

Cited by 404 publications

References 82 publications

New developments in the Casimir effect

New developments in the Casimir effect

Lagrange multiplier and Wess-Zumino variable as extra dimensions in the torus universe

Induced gravity II: grand unification

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