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Title: Constraining cosmic curvature by using age of galaxies and gravitational lenses

Abstract

We use two model-independent methods to constrain the curvature of the universe. In the first method, we study the evolution of the curvature parameter (Ω {sub k} {sup 0}) with redshift by using the observations of the Hubble parameter and transverse comoving distances obtained from the age of galaxies. Secondly, we also use an indirect method based on the mean image separation statistics of gravitationally lensed quasars. The basis of this methodology is that the average image separation of lensed images will show a positive, negative or zero correlation with the source redshift in a closed, open or flat universe respectively. In order to smoothen the datasets used in both the methods, we use a non-parametric method namely, Gaussian Process (GP). Finally from first method we obtain Ω {sub k} {sup 0} = 0.025±0.57 for a presumed flat universe while the cosmic curvature remains constant throughout the redshift region 0 < z < 1.37 which indicates that the universe may be homogeneous. Moreover, the combined result from both the methods suggests that the universe is marginally closed. However, a flat universe can be incorporated at 3σ level.

Authors:
; ;  [1];  [2]
  1. Department of Physics and Astrophysics, University of Delhi, Delhi 110007 (India)
  2. Deen Dayal Upadhyaya College, University of Delhi, Sector-3, Dwarka, Delhi 110078 (India)
Publication Date:
OSTI Identifier:
22679982
Resource Type:
Journal Article
Resource Relation:
Journal Name: Journal of Cosmology and Astroparticle Physics; Journal Volume: 2017; Journal Issue: 03; Other Information: Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
79 ASTROPHYSICS, COSMOLOGY AND ASTRONOMY; CORRELATIONS; DATASETS; DISTANCE; GALAXIES; GAUSSIAN PROCESSES; GLOBAL POSITIONING SYSTEM; GRAVITATIONAL LENSES; IMAGES; QUASARS; RED SHIFT; STATISTICS; UNIVERSE

Citation Formats

Rana, Akshay, Mahajan, Shobhit, Mukherjee, Amitabha, and Jain, Deepak, E-mail: arana@physics.du.ac.in, E-mail: djain@ddu.du.ac.in, E-mail: shobhit.mahajan@gmail.com, E-mail: amimukh@gmail.com. Constraining cosmic curvature by using age of galaxies and gravitational lenses. United States: N. p., 2017. Web. doi:10.1088/1475-7516/2017/03/028.
Rana, Akshay, Mahajan, Shobhit, Mukherjee, Amitabha, & Jain, Deepak, E-mail: arana@physics.du.ac.in, E-mail: djain@ddu.du.ac.in, E-mail: shobhit.mahajan@gmail.com, E-mail: amimukh@gmail.com. Constraining cosmic curvature by using age of galaxies and gravitational lenses. United States. doi:10.1088/1475-7516/2017/03/028.
Rana, Akshay, Mahajan, Shobhit, Mukherjee, Amitabha, and Jain, Deepak, E-mail: arana@physics.du.ac.in, E-mail: djain@ddu.du.ac.in, E-mail: shobhit.mahajan@gmail.com, E-mail: amimukh@gmail.com. Wed . "Constraining cosmic curvature by using age of galaxies and gravitational lenses". United States. doi:10.1088/1475-7516/2017/03/028.
@article{osti_22679982,
title = {Constraining cosmic curvature by using age of galaxies and gravitational lenses},
author = {Rana, Akshay and Mahajan, Shobhit and Mukherjee, Amitabha and Jain, Deepak, E-mail: arana@physics.du.ac.in, E-mail: djain@ddu.du.ac.in, E-mail: shobhit.mahajan@gmail.com, E-mail: amimukh@gmail.com},
abstractNote = {We use two model-independent methods to constrain the curvature of the universe. In the first method, we study the evolution of the curvature parameter (Ω {sub k} {sup 0}) with redshift by using the observations of the Hubble parameter and transverse comoving distances obtained from the age of galaxies. Secondly, we also use an indirect method based on the mean image separation statistics of gravitationally lensed quasars. The basis of this methodology is that the average image separation of lensed images will show a positive, negative or zero correlation with the source redshift in a closed, open or flat universe respectively. In order to smoothen the datasets used in both the methods, we use a non-parametric method namely, Gaussian Process (GP). Finally from first method we obtain Ω {sub k} {sup 0} = 0.025±0.57 for a presumed flat universe while the cosmic curvature remains constant throughout the redshift region 0 < z < 1.37 which indicates that the universe may be homogeneous. Moreover, the combined result from both the methods suggests that the universe is marginally closed. However, a flat universe can be incorporated at 3σ level.},
doi = {10.1088/1475-7516/2017/03/028},
journal = {Journal of Cosmology and Astroparticle Physics},
number = 03,
volume = 2017,
place = {United States},
year = {Wed Mar 01 00:00:00 EST 2017},
month = {Wed Mar 01 00:00:00 EST 2017}
}