Formation of a star and planets around it through a gravitational instability in a disk of gas and dust

Griv, Evgeny

doi:10.1016/j.pss.2006.03.011

Cited by 5 publications

(3 citation statements)

References 145 publications

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“…And considering some possible variation of the local density of energy, different speed of gravity waves and mass dependent gravity forces can be predicted [60,121,[156][157][158][159]. And also, other quantum phenomena such as vortex phenomena will likely be predictable, and with which formation of spiral galaxies can be explained [22,[160][161][162][163].…”

Section: Gravity and Gravity Wavesmentioning

confidence: 99%

An Approach For Unity Field Theory With New Quantumvacuum Energy Aether Concept

Neuville¹

2022

J Mathe & Comp Appli

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Theories of relativity and quantum physics are basing on some complex abstract mathematical formalism which can be quite confusing and not always satisfactory concerning the interpretation of observed corresponding physical effects. For a revised approach of them, we present a new quantum vacuum energy Aether concept we will discuss qualitatively avoiding some abstract mathematical formalism often far from intuitive physical common sense. This is essentially concerning: the relative velocity of light and the Aether disprove, the particle/wave duality, the single particle interference quantum phenomena, the generalized confusion between absolute quantum determinism and undetermined probabilistic measurements of quantum states and the paradoxical possibility for a same quantum system to have at same time different states. Notwithstanding different suggested flaws about the principle of energy and impulse conservation and concerning the optical doppler effect and the postulate of an absolute light speed limit which is contradicted with some observation of superluminal particle transportation velocity. Paradoxical aspects of both theories of the quantum mechanics and theory of relativity are suggested to be sorted out with the rehabilitation of an absolute space reference and a newly defined Aether concept, basing on the equivalence between density of mass and density of quantum vacuum energy. Different aspects of the Field Theory and wave /mass /electric particles interactions are suggested to be interpreted in terms of Aether hydrodynamical energy displacement, fluctuation and waves. Electric charge and mass of particles and their kinetic energy are described in terms of energy of an associated Aether 3D transversal and/or longitudinal wave-packet moving with its group velocity in form of Aether vortices. This model is expected to sort out contradiction about different quantum phenomena and to open the way for new description and interpretation of corresponding new experimental results.

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Section: Gravity and Gravity Wavesmentioning

confidence: 99%

An Approach For Unity Field Theory With New Quantumvacuum Energy Aether Concept

Neuville¹

2022

J Mathe & Comp Appli

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“…Only a handful of authors have attempted to bridge this gap (e.g. Larson 2002;Griv 2007) although there exists an acknowledgment that the presence of planets can affect the accretion rate on to the star (e.g. Goodman & Rafikov 2001;Nayakshin & Lodato 2012;Nayakshin 2013).…”

Section: Context and Assumptionsmentioning

confidence: 99%

An exoplanet's response to anisotropic stellar mass loss during birth and death

Veras

Hadjidemetriou

Tout

2013

Monthly Notices of the Royal Astronomical Society

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The birth and death of planets may be affected by mass outflows from their parent stars during the T-Tauri or post-main-sequence phases of stellar evolution. These outflows are often modelled to be isotropic, but this assumption is not realistic for fast rotators, bipolar jets and supernovae. Here we derive the general equations of motion for the time evolution of a single planet, brown dwarf, comet or asteroid perturbed by anisotropic mass loss in terms of a complete set of planetary orbital elements, the ejecta velocity, and the parent star's co-latitude and longitude. We restrict our application of these equations to 1) rapidly rotating giant stars, and 2) arbitrarily-directed jet outflows. We conclude that the isotropic mass-loss assumption can safely be used to model planetary motion during giant branch phases of stellar evolution within distances of hundreds of au. In fact, latitudinal mass loss variations anisotropically affect planetary motion only if the mass loss is asymmetric about the stellar equator. Also, we demonstrate how constant-velocity, asymmetric bipolar outflows in young systems incite orbital inclination changes. Consequently, this phenomenon readily tilts exoplanetary orbits external to a nascent disc on the order of degrees.

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“…The Lindblad resonances occur when the mean motion of the wave and that of the disk particles are in the ratio .24) and in Saturn's rings κ ≈ Ω. The most important are strong loworder resonances with m < 10 (see Goldreich & Tremaine 1982;Shu 1984;and Griv 2007b …”

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confidence: 99%

Fine-scale density wave structure of Saturn's rings: A hydrodynamic theory

Griv

Gedalin

2010

A&A

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Aims. We examine the linear stability of the Saturnian ring disk of mutually gravitating and physically colliding particles with special emphasis on its fine-scale ∼100 m density wave structure, that is, almost regularly spaced, aligned cylindric density enhancements and optically-thin zones with the width and the spacing between them of roughly several tens particle diameters. Methods. We analyze the Jeans' instabilities of gravity perturbations (e.g., those produced by a spontaneous disturbance) analytically by using the Navier-Stokes dynamical equations of a compressible fluid. The theory is not restricted by any assumptions about the thickness of the system. We consider a simple model of the system consisting of a three-dimensional ring disk that is weakly inhomogeneous and whose structure is analyzed by making a horizontally local short-wave approximation. Results. We demonstrate that the disk is probably unstable and that gravity perturbations grow effectively within a few orbital periods. We find that self-gravitation plays a key role in the formation of the fine structure. The predictions of the theory are compared with observations of Saturn's rings by the Cassini spacecraft and are found to be in good agreement. In particular, it appears very likely that some of the quasi-periodic microstructures observed in Saturn's A and B rings -both axisymmetric and nonaxisymmetric onesare manifestations of these effects. We argue that the quasi-periodic density enhancements revealed in Cassini data are flattened structures, with a height to width ratio of about 0.3. One should analyze high-resolution of the order of 10 m data acquired for the A and B rings (and probably C ring as well) to confirm this prediction. We also show that the gravitational instability is a potential cluster-forming mechanism leading to the formation of porous 100-m-diameter moonlets of preferred mass ∼10 7 g each embedded in the outer A ring, although this has yet to be directly measured.

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Formation of a star and planets around it through a gravitational instability in a disk of gas and dust

Cited by 5 publications

References 145 publications

An Approach For Unity Field Theory With New Quantumvacuum Energy Aether Concept

An Approach For Unity Field Theory With New Quantumvacuum Energy Aether Concept

An exoplanet's response to anisotropic stellar mass loss during birth and death

Fine-scale density wave structure of Saturn's rings: A hydrodynamic theory

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