Authentication email has already been sent, please check your email box: and activate it as soon as possible.
You can login to My Profile and manage your email alerts.
If you haven’t received the email, please:
|
|
There are 6 papers published in subject: > since this site started. |
Results per page: |
Select Subject |
Select/Unselect all | For Selected Papers |
Saved Papers
Please enter a name for this paper to be shown in your personalized Saved Papers list
|
1. The relativistic astrodynamics of spiral tracks, localized equivalence principle and the dark matter problem of our Milky Way galaxy | |||
Zhiping Li, Ran Li | |||
Astronomy 23 April 2014 | |||
Show/Hide Abstract | Cite this paper︱Full-text: PDF (0 B) | |||
Abstract:The relativistic astrodynamics of spiral track is discussed in this thesis. This study shows that, in outer regions of the Milky Way galaxy, the relativistic effects, in particular, the aberration effect of relativity are the causes of logarithmic spiral tracks of the celestial bodies, which result in the flat rotation curves of the galaxy and the phenomena of dark matter in universe. As an important conclusion derived, at large galactic and cosmological distances, the ratio of the inertia to the gravitational mass of an object appears the phenomenon of running between the different local inertial viewers. Such a geodesic deviation from the equivalence principle is the performance of relative acceleration between two local Lorentz frame in the non-local sense. The key constants of our Milky Way galaxy are determined by this theory without dark matter, including the mass of Milky Way galaxy and the galactic orbital parameters of logarithmic spiral track in outer regions of the galaxy. | |||
TO cite this article:Zhiping Li, Ran Li. The relativistic astrodynamics of spiral tracks, localized equivalence principle and the dark matter problem of our Milky Way galaxy[OL].[23 April 2014] http://en.paper.edu.cn/en_releasepaper/content/4593462 |
2. Gas accretion onto a planet pair: the final mass ratio and orbital configuration | |||
Hui Zhang, Yuanyuan Chen, Ji-Lin Zhou | |||
Astronomy 26 November 2012 | |||
Show/Hide Abstract | Cite this paper︱Full-text: PDF (0 B) | |||
Abstract:We present a summary of our recent investigations on the evolutions of orbit and mass ratio of a gas-accreting planet pair. The main aim of this study is to explain the mass configurations of the exoplanet pairs that are in compact orbital configurations(i.e. in or near the mean motion resonances(MMRs)). We assume the two planet cores had already reached the critical masses($15 or 30$ Earth masses), so that we only focus on the runaway gas accretion phase. To be consistent, We begin with the cases with single planet core embedded in various disks. The results show that large planet core usually results in small gas planet and dominant factor of the final planet mass is the viscosity of the disk. Our further simulations with two planet cores show that, if the two cores accrete gas simultaneously, they will undergo convergent migration and eventually be trapped in the $2:1$ MMR. Furthermore, their mass ratio changes during the migration and the final mass of the outer planet is always more massive than or equal to that of the inner one. | |||
TO cite this article:Hui Zhang, Yuanyuan Chen, Ji-Lin Zhou. Gas accretion onto a planet pair: the final mass ratio and orbital configuration[OL].[26 November 2012] http://en.paper.edu.cn/en_releasepaper/content/4495997 |
3. Gap formation in a self-gravitating disk and the associatedmigration of the embedded giant planet | |||
Zhang Hui ,Liu Huigen ,Zhou Jilin | |||
Astronomy 23 November 2012 | |||
Show/Hide Abstract | Cite this paper︱Full-text: PDF (0 B) | |||
Abstract:We present the results of our recent study on theinteractions between a giant planet and a self-gravitating gas disk. Weinvestigate how the disk's self-gravity affects the gap formationprocess and the migration of the giant planet.Two series of 1-D and 2-D hydrodynamic simulations are performed. Weselect several surface densities and focus on the gravitationally stableregion. To obtain more reliable gravity torques exerted on the planet, arefined treatment of disk's gravity is adopted in the vicinity of theplanet.Our results indicate that the net effect of the disk's self-gravity on thegap formation process depends on the surface density of the disk. Wenotice that there are two critical values, ∑ I and ∑II}. When the surface density of the disk is lower than the first one, ∑0< ∑I, the effect of self-gravity suppresses the formation of a gap.When∑0 > ∑I, the self-gravity of the gas tends to benefit thegap formation process and enlarge the width/depth of the gap. Accordingto our 1-D and 2-D simulations, we estimate the first critical surfacedensity ∑I ≈0.8MMSN. This effect increases until thesurface density reaches the second critical value ∑II. When ∑0 > ∑II, the gravitational turbulence in the diskbecomes dominant and the gap formation process is suppressed again. Our2-D simulations show that this critical surface density is around 3.4MMSN. We also study the associated orbital evolution of a giantplanet. Under the effect of the disk's self-gravity, the migration rateof the giant planet increases when the disk is dominated bygravitational turbulence. We show that the migration timescaleassociates with the effective viscosity and can be up to 10 4 yr. | |||
TO cite this article:Zhang Hui ,Liu Huigen ,Zhou Jilin . Gap formation in a self-gravitating disk and the associatedmigration of the embedded giant planet[OL].[23 November 2012] http://en.paper.edu.cn/en_releasepaper/content/4495964 |
4. New Periodic Solutions for Planar 5–Body and 7-Body Problems | |||
Su Xia,Zhang Shiqing | |||
Astronomy 11 March 2009 | |||
Show/Hide Abstract | Cite this paper︱Full-text: PDF (0 B) | |||
Abstract:For planar Newtonian N + 2-body (N=3,5)problems with some mass ratios, we prove the existence of new non-collision periodic solutions such that N bodies with equal masses move on one loop and the other 2 bodies with equal masses move on the other one or two closed curves and have some given winding numbers and symmetries. | |||
TO cite this article:Su Xia,Zhang Shiqing. New Periodic Solutions for Planar 5–Body and 7-Body Problems[OL].[11 March 2009] http://en.paper.edu.cn/en_releasepaper/content/30164 |
5. Variational Minimizing Solutions for Planar Circular Restricted 3-Body Problems | |||
Zhang Shiqing | |||
Astronomy 03 March 2009 | |||
Show/Hide Abstract | Cite this paper︱Full-text: PDF (0 B) | |||
Abstract:We use some inequalities to study planar Newtonian circular restricted 3- body problems with two equal primaries, we prove that the minimizer of the Lagrangian action on “8” type symmetric loop spaces of the rotational coordinate systems is just at the center of masses, which implies that we must add topological conditions in order to get the true “8”–type solutions. | |||
TO cite this article:Zhang Shiqing. Variational Minimizing Solutions for Planar Circular Restricted 3-Body Problems[OL].[ 3 March 2009] http://en.paper.edu.cn/en_releasepaper/content/29855 |
6. Periodic Solutions for Some Second Order Hamiltonian Systems | |||
Zhang Shiqing | |||
Astronomy 27 February 2009 | |||
Show/Hide Abstract | Cite this paper︱Full-text: PDF (0 B) | |||
Abstract:We use saddle point theorems of Benci-Rabinowitz and Silva to study the existence of periodic solutions with a fixed energy for a few second order Hamiltonian conservative systems without any symmetry,the key difficulty of the proof is proving Palais-Smale condition and the nonconstant property for the minimax critical point. | |||
TO cite this article:Zhang Shiqing. Periodic Solutions for Some Second Order Hamiltonian Systems [OL].[27 February 2009] http://en.paper.edu.cn/en_releasepaper/content/29753 |
Select/Unselect all | For Selected Papers |
Saved Papers
Please enter a name for this paper to be shown in your personalized Saved Papers list
|
|
Results per page: |
About Sciencepaper Online | Privacy Policy | Terms & Conditions | Contact Us
© 2003-2012 Sciencepaper Online. unless otherwise stated