Why Unsharp Observables?

Carmeli, Claudio; Heinonen, Teiko; Toigo, Alessandro

doi:10.1007/s10773-007-9365-7

Cited by 7 publications

(10 citation statements)

References 16 publications

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“…Carmeli and Kuzmenko [9] have Recently shown that the cosmological relativistic theory [10] predicts Λ = 1.934 × 10 −35 s −2 which is in agreement with the measurements recently obtained by the High-z Supernova Team and Supernova Cosmological Project [1]- [4]. There have been Several ansätz suggested in which the Λ term decays with time [11]- [25].…”

Section: Introductionsupporting

confidence: 83%

L.R.S. Bianchi type II stiff fluid cosmological model with decaying vacuum energy density Λ in general relativity

Amirhashchi

2011

Physics Letters B

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Locally rotationally symmetric (L.R.S.) Bianchi type II stiff fluid cosmological model is investigated. To get the deterministic model of the universe, we have assumed a condition A = B m between metric potentials A, B where n is the constant. It is shown that the vacuum energy density Λ is positive and proportional to 1 t 2 . The values of deceleration parameter q, matter-energy density Ωm and dark-energy density ΩΛ are found to be in good agreement with the values obtain from 5-years WMAP observations. the predicted value of the jerk parameter agrees with the SNLS SNIa and X-ray galaxy cluster distance data but does not with the SNIa gold sample data. In general, the model represent accelerating, shearing and non-rotating universe.The physical and geometrical behavior of these models are also discussed.

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Section: Introductionsupporting

confidence: 83%

L.R.S. Bianchi type II stiff fluid cosmological model with decaying vacuum energy density Λ in general relativity

Amirhashchi

2011

Physics Letters B

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“…Hence Λ is considered to be the function of time for spatially homogeneous expanding universe. Carmeli and Kuzmenko [24] have shown that the cosmological relativistic theory predicts Λ = 1.934 × 10 −35 s −2 which is in agreement with the measurements recently obtained by the High-Z supernova team and supernova cosmological project [25]. A number of authors have studied cosmological models with time dependent cosmological term viz.…”

Section: Introductionsupporting

confidence: 81%

Bianchi type V viscous fluid cosmological models in presence of decaying vacuum energy

Bali

Singh

2012

Astrophys Space Sci

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Bianchi type V viscous fluid cosmological model for barotropic fluid distribution with varying cosmological term Λ is investigated. We have examined a cosmological scenario proposing a variation law for Hubble parameter H in the background of homogeneous, anisotropic Bianchi type V space-time. The model isotropizes asymptotically and the presence of shear viscosity accelerates the isotropization. The model describes a unified expansion history of the universe indicating initial decelerating expansion and late time accelerating phase. Cosmological consequences of the model are also discussed.

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“…But, compatibility with other areas of physics demands that Λ should be slowly time decreasing [24]. Moreover, the currently observed small value of Λ[25] [26] suggests that it has decreased slowly from a very high value to its present nearly zero value. This type of time dependency of Λ has a similarity with that of the gravitational constant G as proposed by Dirac in his LNH [24].…”

Section: Dirac's Lnh and The Coupling Constant ξmentioning

confidence: 99%

On the electrodynamics of moving particles in a quasi flat spacetime with Lorentz violation and its cosmological implications

Cruz¹

2016

Int. J. Mod. Phys. D

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This research aims to develop a new approach towards a consistent coupling of electromagnetic and gravitational fields, by using an electron that couples with a weak gravitational potential by means of its electromagnetic field. To accomplish this, we must first build a new model which provides the electromagnetic nature of both the mass and the energy of the electron, and which is implemented with the idea of γ-photon decay into an electron-positron pair. After this, we place the electron (or positron) in the presence of a weak gravitational potential given in the intergalactic medium, so that its electromagnetic field undergoes a very small perturbation, thus leading to a slight increase in the field's electromagnetic energy density. This perturbation takes place by means of a tiny coupling constant ξ because gravity is a very weak interaction compared with the electromagnetic one. Thus, we realize that ξ is a new dimensionless universal constant, which reminds us of the fine structure constant α; however, ξ is much smaller than α because ξ takes into account gravity, i.e. ξ ∝ √ G. We find ξ = V /c ∼ = 1.5302 × 10 −22 , where c is the speed of light and V ∝ √ G( ∼ = 4.5876 × 10 −14 m/s) is a universal minimum speed that represents the lowest limit of speed for any particle. Such a minimum speed, unattainable by particles, represents a preferred reference frame associated with a background field that breaks the Lorentz symmetry. The metric of the flat spacetime shall include the presence of a uniform vacuum energy density, which leads to a negative pressure at cosmological scales (cosmological anti-gravity). The tiny values of the cosmological constant and the vacuum energy density will be successfully obtained in agreement with the observational data.

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Why Unsharp Observables?

Cited by 7 publications

References 16 publications

L.R.S. Bianchi type II stiff fluid cosmological model with decaying vacuum energy density Λ in general relativity

L.R.S. Bianchi type II stiff fluid cosmological model with decaying vacuum energy density Λ in general relativity

Bianchi type V viscous fluid cosmological models in presence of decaying vacuum energy

On the electrodynamics of moving particles in a quasi flat spacetime with Lorentz violation and its cosmological implications

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