<p>So i am working on reproducing a paper <a href="https://arxiv.org/abs/2009.14826" rel="nofollow noreferrer">(Secrest, N. J., von Hausegger, S., Rameez, M., Mohayaee, R., Sarkar, S., &amp; Colin, J. (2021). A test of the cosmological principle with quasars. The Astrophysical Journal Letters, 908(2), L51.)</a>  and I have this equation
<span class="math-container">$$\sum_p\left[n_p - \left(A_0 + \sum_{j=1}^3 A_{1,j}d_{j,p}\right)\right]^2$$</span></p>
<p>the paper describes the process of how they implemented it. However I cant grasp my head around it. I have done all the previous steps but this is where I am stuck.
I have the number densities but I can't seem to figure out how to get the other variables namely, <span class="math-container">$A_0$</span> and the <span class="math-container">$A_{1j}$</span> and <span class="math-container">$d_j$</span>.</p>
<p>Can someone here help me with this?</p>

CC BY-SA 4.0
2023-05-04T15:13:25.810Z
I'm not sure.. what exactly is the question? Right after the equation the paper explains what the symbols indicate. So you ask how to calculate a mean density i.e., $A_0$? You might want to explain a bit more in detail your thought processes and current status of your progess in your endeavour as it might explain the exact issue better
planetmaker
CC BY-SA 4.0
2023-05-04T16:03:48.073Z
@planetmaker I want to know where would I get the values for A0, A1j and dj.
qasidaleem
CC BY-SA 4.0
2023-05-04T16:04:50.850Z
@planetmakeri I want to know what equations or methodology they used to reach their answers
qasidaleem
<astrophysics><cosmology><mathematics><quasars>
Trying to understand how to properly implement this equation to a healpix map
qasidaleem
# Trying to understand how to properly implement this equation to a healpix map

(Asked by: username_0 on 2023-05-04)

So i am working on reproducing a paper [(Secrest, N. J., von Hausegger, S., Rameez, M., Mohayaee, R., Sarkar, S., & Colin, J. (2021). A test of the cosmological principle with quasars. The Astrophysical Journal Letters, 908(2), L51.)](https://arxiv.org/abs/2009.14826) and I have this equation
$$\sum\_p\left[n\_p - \left(A\_0 + \sum\_{j=1}^3 A\_{1,j}d\_{j,p}\right)\right]^2$$

the paper describes the process of how they implemented it. However I cant grasp my head around it. I have done all the previous steps but this is where I am stuck.
I have the number densities but I can't seem to figure out how to get the other variables namely, $A\_0$ and the $A\_{1j}$ and $d\_j$.

Can someone here help me with this?

**Tags:** astrophysics, cosmology, mathematics, quasars

> **Comments:**
> **username_1**: I'm not sure.. what exactly is the question? Right after the equation the paper explains what the symbols indicate. So you ask how to calculate a mean density i.e., $A_0$? You might want to explain a bit more in detail your thought processes and current status of your progess in your endeavour as it might explain the exact issue better  
> **username_0**: @username_1 I want to know where would I get the values for A0, A1j and dj.  
> **username_0**: @username_1i I want to know what equations or methodology they used to reach their answers  

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## 0 answers

