# Revisiting dark energy models using differential ages of galaxies

## Abstract

In this work, we use a test based on the differential ages of galaxies for distinguishing the dark energy models. As proposed by Jimenez and Loeb in [1], relative ages of galaxies can be used to put constraints on various cosmological parameters. In the same vein, we reconstruct H {sub 0} {sub dt} / dz and its derivative ( H {sub 0} {sub d} {sup 2} {sup t} / dz {sup 2}) using a model independent technique called non-parametric smoothing . Basically, dt / dz is the change in the age of the object as a function of redshift which is directly linked with the Hubble parameter. Hence for reconstruction of this quantity, we use the most recent H ( z ) data. Further, we calculate H {sub 0} {sub dt} / dz and its derivative for several models like Phantom, Einstein de Sitter (EdS), ΛCDM, Chevallier-Polarski-Linder (CPL) parametrization, Jassal-Bagla-Padmanabhan (JBP) parametrization and Feng-Shen-Li-Li (FSLL) parametrization. We check the consistency of these models with the results of reconstruction obtained in a model independent way from the data. It is observed that H {sub 0} {sub dt} / dz as a tool is not able to distinguish between the ΛCDM, CPL,more »

- Authors:

- Department of Physics and Astrophysics, University of Delhi, Delhi 110007 (India)
- Deen Dayal Upadhyaya College, University of Delhi, Sector-3, Dwarka, Delhi 110078 (India)
- University of Silesia, Institute of Physics, Uniwersytecka 4 PL-40-007 Katowice (Poland)

- Publication Date:

- OSTI Identifier:
- 22679998

- 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; COSMOLOGICAL MODELS; DE SITTER SPACE; ENERGY MODELS; GALAXIES; NONLUMINOUS MATTER; PHANTOMS; RED SHIFT

### Citation Formats

```
Rani, Nisha, Mahajan, Shobhit, Mukherjee, Amitabha, Jain, Deepak, and Biesiada, Marek, E-mail: nisharani3105@gmail.com, E-mail: djain@ddu.du.ac.in, E-mail: shobhit.mahajan@gmail.com, E-mail: amimukh@gmail.com, E-mail: marek.biesiada@us.edu.pl.
```*Revisiting dark energy models using differential ages of galaxies*. United States: N. p., 2017.
Web. doi:10.1088/1475-7516/2017/03/005.

```
Rani, Nisha, Mahajan, Shobhit, Mukherjee, Amitabha, Jain, Deepak, & Biesiada, Marek, E-mail: nisharani3105@gmail.com, E-mail: djain@ddu.du.ac.in, E-mail: shobhit.mahajan@gmail.com, E-mail: amimukh@gmail.com, E-mail: marek.biesiada@us.edu.pl.
```*Revisiting dark energy models using differential ages of galaxies*. United States. doi:10.1088/1475-7516/2017/03/005.

```
Rani, Nisha, Mahajan, Shobhit, Mukherjee, Amitabha, Jain, Deepak, and Biesiada, Marek, E-mail: nisharani3105@gmail.com, E-mail: djain@ddu.du.ac.in, E-mail: shobhit.mahajan@gmail.com, E-mail: amimukh@gmail.com, E-mail: marek.biesiada@us.edu.pl. Wed .
"Revisiting dark energy models using differential ages of galaxies". United States.
doi:10.1088/1475-7516/2017/03/005.
```

```
@article{osti_22679998,
```

title = {Revisiting dark energy models using differential ages of galaxies},

author = {Rani, Nisha and Mahajan, Shobhit and Mukherjee, Amitabha and Jain, Deepak and Biesiada, Marek, E-mail: nisharani3105@gmail.com, E-mail: djain@ddu.du.ac.in, E-mail: shobhit.mahajan@gmail.com, E-mail: amimukh@gmail.com, E-mail: marek.biesiada@us.edu.pl},

abstractNote = {In this work, we use a test based on the differential ages of galaxies for distinguishing the dark energy models. As proposed by Jimenez and Loeb in [1], relative ages of galaxies can be used to put constraints on various cosmological parameters. In the same vein, we reconstruct H {sub 0} {sub dt} / dz and its derivative ( H {sub 0} {sub d} {sup 2} {sup t} / dz {sup 2}) using a model independent technique called non-parametric smoothing . Basically, dt / dz is the change in the age of the object as a function of redshift which is directly linked with the Hubble parameter. Hence for reconstruction of this quantity, we use the most recent H ( z ) data. Further, we calculate H {sub 0} {sub dt} / dz and its derivative for several models like Phantom, Einstein de Sitter (EdS), ΛCDM, Chevallier-Polarski-Linder (CPL) parametrization, Jassal-Bagla-Padmanabhan (JBP) parametrization and Feng-Shen-Li-Li (FSLL) parametrization. We check the consistency of these models with the results of reconstruction obtained in a model independent way from the data. It is observed that H {sub 0} {sub dt} / dz as a tool is not able to distinguish between the ΛCDM, CPL, JBP and FSLL parametrizations but, as expected, EdS and Phantom models show noticeable deviation from the reconstructed results. Further, the derivative of H {sub 0} {sub dt} / dz for various dark energy models is more sensitive at low redshift. It is found that the FSLL model is not consistent with the reconstructed results, however, the ΛCDM model is in concordance with the 3σ region of the reconstruction at redshift z ≥ 0.3.},

doi = {10.1088/1475-7516/2017/03/005},

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}

}