scholarly journals The first simultaneous measurement of Hubble constant and post-Newtonian parameter from time-delay strong lensing

2020 ◽  
Vol 497 (1) ◽  
pp. L56-L61 ◽  
Author(s):  
Tao Yang ◽  
Simon Birrer ◽  
Bin Hu
Keyword(s):  
General Relativity ◽  
Time Delay ◽  
Cosmological Model ◽  
Gravitational Lensing ◽  
Hubble Constant ◽  
Stellar Kinematics ◽  
Local Universe ◽  
Dynamical Mass ◽  
Strong Gravitational Lensing ◽  
Strong Lensing

ABSTRACT Strong gravitational lensing has been a powerful probe of cosmological models and gravity. To date, constraints in either domain have been obtained separately. We propose a new methodology through which the cosmological model, specifically the Hubble constant, and post-Newtonian parameter can be simultaneously constrained. Using the time-delay cosmography from strong lensing combined with the stellar kinematics of the deflector lens, we demonstrate that the Hubble constant and post-Newtonian parameter are incorporated in two distance ratios that reflect the lensing mass and dynamical mass, respectively. Through the re-analysis of the four publicly released lenses distance posteriors from the H0LiCOW (H0 Lenses in COSMOGRAIL’s Wellspring) collaboration, the simultaneous constraints of Hubble constant and post-Newtonian parameter are obtained. Our results suggest no deviation from the general relativity; $\gamma _{\tt {PPN}}=0.87^{+0.19}_{-0.17}$ with a Hubble constant that favours the local Universe value, $H_0=73.65^{+1.95}_{-2.26}$ km s−1 Mpc−1. Finally, we forecast the robustness of gravity tests by using the time-delay strong lensing for constraints we expect in the next few years. We find that the joint constraint from 40 lenses is able to reach the order of $7.7{{\ \rm per\ cent}}$ for the post-Newtonian parameter and $1.4{{\ \rm per\ cent}}$ for the Hubble constant.

scholarly journals HOLISMOKES

2020 ◽  
Vol 644 ◽  
pp. A162
Author(s):  
S. H. Suyu ◽  
S. Huber ◽  
R. Cañameras ◽  
M. Kromer ◽  
S. Schuldt ◽  
...  
Keyword(s):  
Time Delay ◽  
Gravitational Lensing ◽  
Early Phase ◽  
Rest Frame ◽  
Hubble Constant ◽  
Angular Diameter ◽  
Strong Gravitational Lensing ◽  
Space And Time ◽  
Precise Time

We present the HOLISMOKES programme on strong gravitational lensing of supernovae (SNe) as a probe of SN physics and cosmology. We investigate the effects of microlensing on early-phase SN Ia spectra using four different SN explosion models. We find that distortions of SN Ia spectra due to microlensing are typically negligible within ten rest-frame days after a SN explosion (< 1% distortion within the 1σ spread and ≲10% distortion within the 2σ spread). This shows the great prospects of using lensed SNe Ia to obtain intrinsic early-phase SN spectra for deciphering SN Ia progenitors. As a demonstration of the usefulness of lensed SNe Ia for cosmology, we simulate a sample of mock lensed SN Ia systems that are expected to have accurate and precise time-delay measurements in the era of the Rubin Observatory Legacy Survey of Space and Time (LSST). Adopting realistic yet conservative uncertainties on their time-delay distances and lens angular diameter distances, of 6.6% and 5%, respectively, we find that a sample of 20 lensed SNe Ia would allow us to constrain the Hubble constant (H0) with 1.3% uncertainty in the flat ΛCDM cosmology. We find a similar constraint on H0 in an open ΛCDM cosmology, while the constraint degrades to 3% in a flat wCDM cosmology. We anticipate lensed SNe to be an independent and powerful probe of SN physics and cosmology in the upcoming LSST era.

scholarly journals STRONG GRAVITATIONAL LENSING AND ITS COSMIC CONSTRAINTS

2013 ◽  
Vol 28 (14) ◽  
pp. 1350057 ◽  
Author(s):  
NANNAN WANG ◽  
LIXIN XU
Keyword(s):  
Cosmological Model ◽  
Gravitational Lensing ◽  
Velocity Dispersion ◽  
Model Space ◽  
Data Sets ◽  
Spatial Curvature ◽  
Strong Gravitational Lensing ◽  
Strong Lensing ◽  
Λcdm Model ◽  
Stellar Velocity

In this paper, we propose a new method to use the strong lensing data sets to constrain a cosmological model. By taking the ratio [Formula: see text] as cosmic observations, one can completely eliminate the uncertainty caused by the relation σSIS= fEσ0which characterizes the relation between the stellar velocity dispersion σ0and the velocity dispersion σSIS. Via our method, a relative tight constraint to the cosmological model space can be obtained, for the spatially flat ΛCDM model as an example [Formula: see text] in 3σ regions. And by using this method, one can also probe the nature of dark energy and the spatial curvature of our Universe.

scholarly journals Generalized model-independent characterization of strong gravitational lenses V: reconstructing the lensing distance ratio by supernovae for a general Friedmann universe

2019 ◽  
Vol 490 (2) ◽  
pp. 1913-1927
Author(s):  
Jenny Wagner ◽  
Sven Meyer
Keyword(s):  
Time Delay ◽  
Cosmological Model ◽  
Gravitational Lensing ◽  
Distance Measure ◽  
Hubble Constant ◽  
Distance Measures ◽  
Gravitational Lenses ◽  
Confidence Bounds ◽  
Distance Ratio ◽  
Model Independent

ABSTRACT We determine the cosmic expansion rate from supernovae of type Ia to set up a data-based distance measure that does not make assumptions about the constituents of the universe, i.e. about a specific parametrization of a Friedmann cosmological model. The scale, determined by the Hubble constant H0, is the only free cosmological parameter left in the gravitational lensing formalism. We investigate to which accuracy and precision the lensing distance ratio D is determined from the Pantheon sample. Inserting D and its uncertainty into the lensing equations for given H0, especially the time-delay equation between a pair of multiple images, allows to determine lens properties, especially differences in the lensing potential (Δϕ), without specifying a cosmological model. We expand the luminosity distances into an analytic orthonormal basis, determine the maximum-likelihood weights for the basis functions by a globally optimal χ2-parameter estimation, and derive confidence bounds by Monte Carlo simulations. For typical strong lensing configurations between z = 0.5 and 1.0, Δϕ can be determined with a relative imprecision of 1.7 per cent, assuming imprecisions of the time delay and the redshift of the lens on the order of 1 per cent. With only a small, tolerable loss in precision, the model-independent lens characterisation developed in this paper series can be generalised by dropping the specific Friedmann model to determine D in favour of a data-based distance ratio. Moreover, for any astrophysical application, the approach presented here, provides distance measures for z ≤ 2.3 that are valid in any homogeneous, isotropic universe with general relativity as theory of gravity.

Strong Gravitational Lensing Time Delay Statistics and the Density Profile of Dark Halos

2002 ◽  
Vol 568 (2) ◽  
pp. 488-499 ◽  
Author(s):  
Masamune Oguri ◽  
Atsushi Taruya ◽  
Yasushi Suto ◽  
Edwin L. Turner
Keyword(s):  
Time Delay ◽  
Density Profile ◽  
Gravitational Lensing ◽  
Strong Gravitational Lensing

scholarly journals Analysis of the Angular Dependence of Time Delay in Gravitational Lensing

2018 ◽  
Author(s):  
Nicola Alchera ◽  
Marco Bonici ◽  
Roberta Cardinale ◽  
Alba Domi ◽  
Nicola Maggiore ◽  
...  
Keyword(s):  
Time Delay ◽  
Angular Dependence ◽  
Gravitational Potential ◽  
Gravitational Lensing ◽  
Degrees Of Freedom ◽  
Hubble Constant ◽  
Smoothness Condition ◽  
Central Potential ◽  
Alternative Formula

We consider an alternative formula for time delay in gravitational lensing. Imposing a smoothness condition on the gravitationally deformed paths followed by the photons from the source to the observer, we show that our formula displays the same degrees of freedom of the standard one. In addition to this, it is shown that the standard expression for time delay is recovered when small angles are involved. These two features strongly support the claim that the formula for time delay studied in this paper is the generalization to arbitrary angles of the standard one, which is valid at small angles. This could therefore result in a useful tool in view of softening the known discrepancy between the various estimates of the Hubble constant. As an aside, two interesting consequences of our proposal for time delay are discussed: the existence of a constraint on the gravitational potential generated by the lens and a formula for the mass of the lens in the case of central potential.

Gravitational lensing, precession of periapsis and time delay due to wormhole in quintessence polytropic spacetime

2019 ◽  
Vol 34 (32) ◽  
pp. 1950264 ◽  
Author(s):  
Tuhina Manna ◽  
Farook Rahaman ◽  
Sabiruddin Molla ◽  
Amna Ali
Keyword(s):  
General Relativity ◽  
Time Delay ◽  
Gravitational Lensing ◽  
Index Formula ◽  
Polytropic Index ◽  
Spherically Symmetric ◽  
Tests Of General Relativity ◽  
Astrophysical Objects ◽  
Polytropic Equation ◽  
State Formula

The classical tests of General Relativity, namely, precession of periapsis, deflection of light and time delay serve to establish observational evidence for the theory of general relativity, so they are considered for several spherically symmetric astrophysical objects. In this paper, we investigate a stationary, spherically symmetric wormhole supported by a quintessence polytropic energy satisfying a polytropic equation of state: [Formula: see text], where [Formula: see text] is the polytropic index and [Formula: see text] is a positive constant such that [Formula: see text]. The solution of such an equation admits the negative null energy, which is the key ingredient for sustaining traversable wormholes. Motivated by the above-mentioned classical tests, we perform similar studies to explore the range of polytropic index [Formula: see text] which gives us promising results. The advance of periapsis with respect to a test particle and angle of deflection is calculated graphically for those values of [Formula: see text] which cannot be obtained analytically. The time delay has also been calculated numerically and tabulated.

scholarly journals Testing the distance–duality relation from strong gravitational lensing, type Ia supernovae and gamma-ray bursts data up to redshift z ∼ 3.6

2017 ◽  
Vol 26 (09) ◽  
pp. 1750097 ◽  
Author(s):  
Xiangyun Fu ◽  
Pengcheng Li
Keyword(s):  
Cosmological Model ◽  
Gravitational Lensing ◽  
Gamma Ray ◽  
Gamma Ray Bursts ◽  
Type Ia Supernovae ◽  
Redshift Range ◽  
Strong Gravitational Lensing ◽  
Type Ia ◽  
Model Independent ◽  
Ia Supernovae

In this paper, we perform a cosmological model-independent test of the cosmic distance–duality relation (CDDR) in terms of the ratio of angular diameter distance (ADD) [Formula: see text] from strong gravitational lensing (SGL) and the ratio of luminosity distance (LD) [Formula: see text] obtained from the joint of type Ia supernovae (SNIa) Union2.1 compilation and the latest Gamma-Ray Bursts (GRBs) data, where the superscripts s and l correspond to the redshifts [Formula: see text] and [Formula: see text] at the source and lens from SGL samples. The purpose of combining GRB data with SNIa compilation is to test CDDR in a wider redshift range. The LD associated with the redshifts of the observed ADD is obtained through two cosmological model-independent methods, namely, method A: binning the SNIa+GRBs data, and method B: reconstructing the function of DL by combining the Crossing Statistic with the smoothing method. We find that CDDR is compatible with the observations at [Formula: see text] confidence level for the power law model which is assumed to describe the mass distribution of lensing systems with method B in a wider redshift range.

scholarly journals Measurements of the Hubble constant and cosmic curvature with quasars: ultracompact radio structure and strong gravitational lensing

2021 ◽  
Vol 503 (2) ◽  
pp. 2179-2186
Author(s):  
Jing-Zhao Qi ◽  
Jia-Wei Zhao ◽  
Shuo Cao ◽  
Marek Biesiada ◽  
Yuting Liu
Keyword(s):  
Gravitational Lensing ◽  
Cold Dark Matter ◽  
Hubble Constant ◽  
Spatial Curvature ◽  
Radio Structure ◽  
Strong Gravitational Lensing ◽  
Flat Universe ◽  
Long Baseline ◽  
Local Distance ◽  
The One

ABSTRACT Although the Hubble constant H0 and spatial curvature ΩK have been measured with very high precision, they still suffer from some tensions. In this paper, we propose an improved method to combine the observations of ultracompact structure in radio quasars and strong gravitational lensing with quasars acting as background sources to determine H0 and ΩK simultaneously. By applying the distance sum rule to the time-delay measurements of seven strong lensing systems and 120 intermediate-luminosity quasars calibrated as standard rulers, we obtain stringent constraints on the Hubble constant (H0 = 78.3 ± 2.9 km s−1 Mpc−1) and the cosmic curvature (ΩK = 0.49 ± 0.24). On the one hand, in the framework of a flat universe, the measured Hubble constant ($H_0=73.6^{+1.8}_{-1.6} \mathrm{\,km\,s^{-1}\,Mpc^{-1}}$) is strongly consistent with that derived from the local distance ladder, with a precision of 2 per cent. On the other hand, if we use the local H0 measurement as a prior, our results are marginally compatible with zero spatial curvature ($\Omega _K=0.23^{+0.15}_{-0.17}$) and there is no significant deviation from a flat universe. Finally, we also evaluate whether strongly lensed quasars would produce robust constraints on H0 and ΩK in the non-flat and flat Λ cold dark matter model, if the compact radio structure measurements are available from very long baseline interferometry observations.

scholarly journals A model-independent constraint on the Hubble constant with gravitational waves from the Einstein Telescope

2020 ◽  
Vol 29 (15) ◽  
pp. 2050105
Author(s):  
Sixuan Zhang ◽  
Shuo Cao ◽  
Jia Zhang ◽  
Tonghua Liu ◽  
Yuting Liu ◽  
...  
Keyword(s):  
Cosmological Model ◽  
Gravitational Wave ◽  
Gravitational Waves ◽  
Simulated Data ◽  
Hubble Constant ◽  
Host Galaxies ◽  
Local Universe ◽  
Binary Neutron Star ◽  
Einstein Telescope ◽  
Model Independent

In this paper, we investigate the expected constraints on the Hubble constant from the gravitational-wave standard sirens, in a cosmological-model-independent way. In the framework of the well-known Hubble law, the GW signal from each detected binary merger in the local universe ([Formula: see text]) provides a measurement of luminosity distance [Formula: see text] and thus the Hubble constant [Formula: see text]. Focusing on the simulated data of gravitational waves from the third-generation gravitational wave detector (the Einstein Telescope, ET), combined with the redshifts determined from electromagnetic counter parts and host galaxies, one can expect the Hubble constant to be constrained at the precision of [Formula: see text] with 20 well-observed binary neutron star (BNS) mergers. Additional standard-siren measurements from other types of future gravitational-wave sources (NS-BH and BBH) will provide more precision constraints of this important cosmological parameter. Therefore, we obtain that future measurements of the luminosity distances of gravitational waves sources will be much more competitive than the current analysis, which makes it expectable more vigorous and convincing constraints on the Hubble constant in a cosmological-model-independent way.

scholarly journals The impact of mass map truncation on strong lensing simulations

2020 ◽  
Vol 644 ◽  
pp. A108
Author(s):  
Lyne Van de Vyvere ◽  
Dominique Sluse ◽  
Sampath Mukherjee ◽  
Dandan Xu ◽  
Simon Birrer
Keyword(s):  
Galaxy Evolution ◽  
Density Profile ◽  
Gravitational Lensing ◽  
Cosmological Parameters ◽  
Strong Gravitational Lensing ◽  
Strong Lensing ◽  
Dynamical Simulations ◽  
The Impact ◽  
Einstein Radius ◽  
Specific Impact

Strong gravitational lensing is a powerful tool to measure cosmological parameters and to study galaxy evolution mechanisms. However, quantitative strong lensing studies often require mock observations. To capture the full complexity of galaxies, the lensing galaxy is often drawn from high resolution, dark matter only or hydro-dynamical simulations. These have their own limitations, but the way we use them to emulate mock lensed systems may also introduce significant artefacts. In this work we identify and explore the specific impact of mass truncation on simulations of strong lenses by applying different truncation schemes to a fiducial density profile with conformal isodensity contours. Our main finding is that improper mass truncation can introduce undesired artificial shear. The amplitude of the spurious shear depends on the shape and size of the truncation area as well as on the slope and ellipticity of the lens density profile. Due to this effect, the value of H0 or the shear amplitude inferred by modelling those systems may be biased by several percents. However, we show that the effect becomes negligible provided that the lens projected map extends over at least 50 times the Einstein radius.

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