Limits on a possible violation of the strong equivalence principle from primordial nucleosynthesis

1992 ◽  
Vol 389 ◽  
pp. 1 ◽  
Author(s):  
A. Serna ◽  
R. Dominguez-Tenreiro
Keyword(s):  
Equivalence Principle ◽  
Primordial Nucleosynthesis ◽  
Strong Equivalence Principle

scholarly journals TORSION, CHERN–SIMONS TERM AND DIFFEOMORPHISM INVARIANCE

2011 ◽  
Vol 26 (06) ◽  
pp. 415-421 ◽  
Author(s):  
PRASANTA MAHATO ◽  
PARTHA BHATTACHARYA
Keyword(s):  
Scalar Field ◽  
Equivalence Principle ◽  
Bianchi Identity ◽  
Diffeomorphism Invariance ◽  
Chern Simons ◽  
Strong Equivalence Principle

In the torsion ⊗ curvature approach of gravity Chern–Simons modification has been considered here. It has been found that Chern–Simons contribution to the Bianchi identity cancels from that of the scalar field part. But "homogeneity and isotropy" consideration of present day cosmology is a consequence of the "strong equivalence principle" and vice versa.

scholarly journals Testing the Strong Equivalence Principle: Detection of the External Field Effect in Rotationally Supported Galaxies

2020 ◽  
Vol 904 (1) ◽  
pp. 51
Author(s):  
Kyu-Hyun Chae ◽  
Federico Lelli ◽  
Harry Desmond ◽  
Stacy S. McGaugh ◽  
Pengfei Li ◽  
...  
Keyword(s):  
External Field ◽  
Equivalence Principle ◽  
Field Effect ◽  
Strong Equivalence Principle

scholarly journals Conquering systematics in the timing of the pulsar triple system J0337+1715: Towards a unique and robust test of the strong equivalence principle

2017 ◽  
Vol 13 (S337) ◽  
pp. 342-343
Author(s):  
N. V. Gusinskaia ◽  
A. M. Archibald ◽  
J. W. T. Hessels ◽  
D. R. Lorimer ◽  
S. M. Ransom ◽  
...  
Keyword(s):  
General Relativity ◽  
Numerical Integration ◽  
Equivalence Principle ◽  
Triple System ◽  
White Dwarfs ◽  
Radio Pulsar ◽  
Radio Telescopes ◽  
Robust Test ◽  
Millisecond Radio ◽  
Strong Equivalence Principle

AbstractPSR J0337+1715 is a millisecond radio pulsar in a hierarchical stellar triple system with two white dwarfs. This system is a unique and excellent laboratory in which to test the strong equivalence principle (SEP) of general relativity. An initial SEP-violation test was performed using direct 3-body numerical integration of the orbit in order to model the more than 25000 pulse times of arrival (TOAs) from three radio telescopes: Arecibo, Green Bank and Westerbork. In this work I present our efforts to quantify the effects of systematics in the TOAs and timing residuals, which limit the precision of an SEP test. In particular, we apply Fourier-based techniques to the timing residuals in order to isolate the effects of systematics that can masquerade as an SEP violation.

scholarly journals An improved test of the strong equivalence principle with the pulsar in a triple star system

2020 ◽  
Vol 638 ◽  
pp. A24 ◽  
Author(s):  
G. Voisin ◽  
I. Cognard ◽  
P. C. C. Freire ◽  
N. Wex ◽  
L. Guillemot ◽  
...  
Keyword(s):  
Equivalence Principle ◽  
Strong Field ◽  
Stellar System ◽  
Sampled Data ◽  
Theory Of Relativity ◽  
Data Set ◽  
Orbital Parameters ◽  
Timing Model ◽  
The Masses ◽  
Strong Equivalence Principle

Context. The gravitational strong equivalence principle (SEP) is a cornerstone of the general theory of relativity (GR). Hence, testing the validity of SEP is of great importance when confronting GR, or its alternatives, with experimental data. Pulsars that are orbited by white dwarf companions provide an excellent laboratory, where the extreme difference in binding energy between neutron stars and white dwarfs allows for precision tests of the SEP via the technique of radio pulsar timing. Aims. To date, the best limit on the validity of SEP under strong-field conditions was obtained with a unique pulsar in a triple stellar system, PSR J0337+1715. We report here on an improvement of this test using an independent data set acquired over a period of 6 years with the Nançay radio telescope. The improvements arise from a uniformly sampled data set, a theoretical analysis, and a treatment that fixes some short-comings in the previously published results, leading to better precision and reliability of the test. Methods. In contrast to the previously published test, we use a different long-term timing data set, developed a new timing model and an independent numerical integration of the motion of the system, and determined the masses and orbital parameters with a different methodology that treats the parameter Δ, describing a possible strong-field SEP violation, identically to all other parameters. Results. We obtain a violation parameter Δ = ( + 0.5 ± 1.8) × 10−6 at 95% confidence level, which is compatible with and improves upon the previous study by 30%. This result is statistics-limited and avoids limitation by systematics as previously encountered. We find evidence for red noise in the pulsar spin frequency, which is responsible for up to 10% of the reported uncertainty. We use the improved limit on SEP violation to place constraints on a class of well-studied scalar-tensor theories, in particular we find ωBD >  140 000 for the Brans-Dicke parameter. The conservative limits presented here fully take into account current uncertainties in the equation for state of neutron-star matter.

Testing the strong equivalence principle by radio ranging

1984 ◽  
Vol 276 ◽  
pp. 1 ◽  
Author(s):  
V. M. Canuto ◽  
I. Goldman ◽  
I. I. Shapiro
Keyword(s):  
Equivalence Principle ◽  
Strong Equivalence Principle
Sign in / Sign up

Export Citation Format

Share Document