9,339 research outputs found
How the orbital period of a test particle is modified by the Dvali-Gabadadze-Porrati gravity?
In addition to the pericentre \omega, the mean anomaly M and, thus, the mean
longitude \lambda, also the orbital period Pb and the mean motion of a test
particle are modified by the Dvali-Gabadadze-Porrati gravity. While the
correction to Pb depends on the mass of the central body and on the geometrical
features of the orbital motion around it, the correction to is independent
of them, up to terms of second order in the eccentricity . The latter one
amounts to about 2\times 10^-3 arcseconds per century. The present-day accuracy
in determining the mean motions of the inner planets of the Solar System from
radar ranging and differential Very Long Baseline Interferometry is
10^-2-5\times 10^-3 arcseconds per century, but it should be improved in the
near future when the data from the spacecraft to Mercury and Venus will be
available.Comment: LaTex, 7 pages, 13 references, no tables, no figures. Section 2.3
added. To appear in JCA
The impact of the new Earth gravity model EIGEN-CG03C on the measurement of the Lense-Thirring effect with some existing Earth satellites
The impact of the latest combined CHAMP/GRACE/terrestrial measurements Earth
gravity model EIGEN-CG03C on the measurement of the Lense-Thirring effect with
some linear combinations of the nodes of some of the existing Earth's
artificial satellites is presented. The 1-sigma upper bound of the systematic
error in the node-node LAGEOS-LAGEOS II combination is 3.9% (4% with
EIGEN-GRACE02S, \sim 6% with EIGEN-CG01C and \sim 9% with GGM02S), while it is
1$% for the node-only LAGEOS-LAGEOS II-Ajisai-Jason-1 combination (2% with
EIGEN-GRACE02S, 1.6% with EIGEN-CG01C and 2.7% with GGM02S).Comment: LaTex2e, 7 pages, 16 references, 1 table. It is an update of the
impact of the even zonal harmonics of the geopotential on the Lense-Thirring
effect with the EIGEN-GGM03C Earth gravity model publicly released on May 11
2005. Typos corrected. Reference added. To appear in General Relativity and
Gravitation, March 200
Spin precession in the Dvali-Gabadadze-Porrati braneworld scenario
In this letter we work out the secular precession of the spin of a gyroscope
in geodesic motion around a central mass in the framework of the
Dvali-Gabadadze-Porrati multidimensional gravity model. Such an effect, which
depends on the mass of the central body and on the orbit radius of the
gyroscope, contrary to the precessions of the orbital elements of the orbit of
a test body, is far too small to be detected.Comment: Latex, 5 pages, no figures, no tables, 10 reference
On Some Critical Issues of the LAGEOS-Based Tests of the Lense-Thirring Effect
We summarize some critical issues pertaining the tests of the general
relativistic Lense-Thirring effect performed by I. Ciufolini and coworkers in
the gravitational field of the Earth with the geodetic satellites LAGEOS and
LAGEOS II tracked with the Satellite Laser Ranging technique.Comment: Latex2e, 14 pages, no figures, no tables, 67 references. I thank M.
Cerdonio for private communication (September 2010
A possible new test of general relativity with Juno
The expansion in multipoles of the gravitational potential of a rotating body
affects the orbital motion of a test particle orbiting it with long-term
perturbations both at a classical and at a relativistic level. In this
preliminary sensitivity analysis, we show that, for the first time, the J2 c^-2
effects could be measured by the ongoing Juno mission in the gravitational
field of Jupiter during its yearlong science phase (10 November 2016-5 October
2017) thanks to its high eccentricity (e=0.947) and to the huge oblateness of
Jupiter (J2=1.47 10^-2). The semi-major axis a and the perijove \omega\ of Juno
are expected to be shifted by \Delta a =700-900 m and \Delta\omega = 50-60
milliarcseconds, respectively, over 1-2 yr. A numerical analysis shows also
that the expected J2c^-2 range-rate signal for Juno should be as large as 280
microns per second during a typical 6 h pass at its closest approach.
Independent analyses previously performed by other researchers about the
measurability of the Lense-Thirring effect showed that the radio science
apparatus of Juno should reach an accuracy in Doppler range-rate measurements
of 1-5 microns per second over such passes. The range-rate signature of the
classical even zonal perturbations is different from the 1PN one. Thus, further
investigations, based on covariance analyses of simulated Doppler data and
dedicated parameters estimation, are worth of further consideration. It turns
out that the J2 c^-2 effects cannot be responsible of the flyby anomaly in the
gravitational field of the Earth. A dedicated spacecraft in a 6678 km X 57103
km polar orbit would experience a geocentric J2 c^-2 range-rate shift of 0.4 mm
s^-1.Comment: LaTex2e, 16 pages, no tables, 2 figures, 39 references. Version
published in Classical and Quantum Gravity (CQG
The relativistic precession of the orbits
The relativistic precession can be quickly inferred from the nonlinear polar
orbit equation without actually solving it.Comment: Accepted for publication in Astrophysics & Space Scienc
Testing General Relativity with Satellite Laser Ranging: Recent Developments
In this paper the most recent developments in testing General Relativity in
the gravitational field of the Earth with the technique of Satellite Laser
Ranging are presented. In particular, we concentrate our attention on some
gravitoelectric and gravitomagnetic post--Newtonian orbital effects on the
motion of a test body in the external field of a central mass.Comment: Latex2e, 10 pages, no figures, no tables. Paper presented at
COSPAR2002 conference held in Houston, TX, from 10 October 2002 to 19 October
2002. To appear in Advance in Space Research. References added and update
Solar System planetary orbital motions and dark matter
In this paper we explicitly work out the effects that a spherically symmetric
distribution of dark matter with constant density would induce on the Keplerian
orbital elements of the Solar System planets and compare them with the latest
results in planetary orbit determination from the EPM2004 ephemerides. It turns
out that the longitudes of perihelia and the mean longitudes are affected by
secular precessions. The resulting upper bounds on dark matter density,
obtained from the EPM2004 formal errors in the determined mean longitude shifts
over 90 years, lie in the range 10^-19-10^-20 g cm^-3 with a peak of 10^-22 g
cm^-3 for Mars. Suitable combinations of the planetary mean longitudes and
perihelia, which cancel out the aliasing impact of some of the unmodelled or
mismodelled forces of the dynamical models of EPM2004, yield a global upper
bound of 7 10^-20 g cm^-3 and 4 10^-19 g cm^-3, respectively.Comment: Latex, 8 pages, 2 tables, no figures, 8 references. Revised version
with improved analysi
An assessment of the measurement of the Lense-Thirring effect in the Earth gravity field, in reply to: ``On the measurement of the Lense-Thirring effect using the nodes of the LAGEOS satellites, in reply to ``On the reliability of the so far performed tests for measuring the Lense-Thirring effect with the LAGEOS satellites'' by L. Iorio,'' by I. Ciufolini and E. Pavlis
In this paper we reply to recent claims by Ciufolini and Pavlis about certain
aspects of the measurement of the general relativistic Lense-Thirring effect in
the gravitational field of the Earth. I) The proposal by such authors of using
the existing satellites endowed with some active mechanism of compensation of
the non-gravitational perturbations as an alternative strategy to improve the
currently ongoing Lense-Thirring tests is unfeasible because of the impact of
the uncancelled even zonal harmonics of the geopotential and of some
time-dependent tidal perturbations. II) It is shown that their criticisms about
the possibility of using the existing altimeter Jason-1 and laser-ranged Ajisai
satellites are groundless.III) Ciufolini and Pavlis also claimed that we would
have explicitly proposed to use the mean anomaly of the LAGEOS satellites in
order to improve the accuracy of the Lense-Thirrring tests. We prove that it is
false. In regard to the mean anomaly of the LAGEOS satellites, Ciufolini
himself did use such an orbital element in some previously published tests.
About the latest test performed with the LAGEOS satellites, IV) we discuss the
cross-coupling between the inclination errors and the first even zonal harmonic
as another possible source of systematic error affecting it with an additional
9% bias. V) Finally, we stress the weak points of the claims about the origin
of the two-nodes LAGEOS-LAGEOS II combination used in that test.Comment: LaTex2e, 22 pages, no figures, no tables. To appear in Planetary and
Space Science. Reference Ries et al. 2003a added and properly cite
The impact of the new CHAMP and GRACE Earth gravity models on the measurement of the general relativistic Lense--Thirring effect with the LAGEOS and LAGEOS II satellites
Among the effects predicted by the General Theory of Relativity for the
orbital motion of a test particle, the post-Newtonian gravitomagnetic
Lense-Thirring effect is very interesting and, up to now, there is not yet an
undisputable experimental direct test of it. To date, the data analysis of the
orbits of the existing geodetic LAGEOS and LAGEOS II satellites has yielded a
test of the Lense-Thirring effect with a claimed accuracy of 20%-30%. According
to some scientists such estimates could be optimistic. Here we wish to discuss
the improvements obtainable in this measurement, in terms of reliability of the
evaluation of the systematic error and reduction of its magnitude, due to the
new CHAMP and GRACE Earth gravity models.Comment: LaTex2e, 6 pages, no figures, no tables. Paper presented at 2nd CHAMP
science meeting, Potsdam, 1-4 September 200
- …