Can Representing Ideas be Possible?

  • Context: Graduate 
  • Thread starter Thread starter BiaCarvalho
  • Start date Start date
  • Tags Tags
    Cosmology Ideas
Click For Summary

Discussion Overview

The discussion revolves around the representation of ideas in the context of the FLRW metric and its application in general relativity. Participants explore the challenges of computing the Einstein tensor from the metric, referencing specific literature and seeking clarification on mathematical steps.

Discussion Character

  • Technical explanation
  • Homework-related
  • Mathematical reasoning

Main Points Raised

  • One participant expresses uncertainty about the possibility of representing ideas effectively.
  • Another participant references the book "Introduction to Gravitation" by Venzo De Sabbata and Maurizio Gasperini, specifically Chapter VII on Non-Static Models of the Universe, as a source for understanding the FLRW metric.
  • Participants inquire about specific sections of the referenced book to clarify the context of the metric.
  • A participant mentions difficulties in computations related to the Einstein tensor, suggesting that the task should be straightforward given the metric.
  • Another participant encourages sharing specific mathematical difficulties to facilitate assistance, noting that computing the Einstein tensor is a fundamental task in general relativity.
  • There is a suggestion to use computer programs like Maxima to aid in the computations.

Areas of Agreement / Disagreement

The discussion remains unresolved, with participants expressing varying levels of understanding and challenges related to the computations. There is no consensus on the specific difficulties faced or the best approach to resolve them.

Contextual Notes

Participants indicate that the computations may be tedious and that there could be confusion in applying the field equations, but do not clarify specific assumptions or steps that may be missing.

BiaCarvalho
Messages
5
Reaction score
0
TL;DR
I was studing the FLRW metric, and I came across the fact that the field equations can be written in the form
imagem_2022-04-27_160952870.png


but I could not develop, is it really possible to represent this way?
 
Space news on Phys.org
BiaCarvalho said:
I was studing the FLRW metric, and I came across the fact...
Where? Please give a reference.
 
  • Like
Likes   Reactions: Orodruin
PeterDonis said:
Where? Please give a reference.
Introduction to Gravitation Venzo De Sabbata, ‎Maurizio Gasperini - 1985
 
BiaCarvalho said:
Introduction to Gravitation Venzo De Sabbata, ‎Maurizio Gasperini - 1985
Which chapter/section in particular?
 
PeterDonis said:
Which chapter/section in particular?
Chapter VII - Non-Static Models Of Universe
1.- The Robertson-Walker metric
 
BiaCarvalho said:
I could not develop
What have you tried? The computations are somewhat tedious, but should be straightforward, since you are given the metric and just need to compute its Einstein tensor.
 
PeterDonis said:
What have you tried? The computations are somewhat tedious, but should be straightforward, since you are given the metric and just need to compute its Einstein tensor.
I was trying to do it like in the book, applying the field equation in the first equation of the chapter, I probably got lost in the math so...
 
BiaCarvalho said:
I probably got lost in the math
If you can post specific places in the math where you're having trouble, we could try to help with that. Computing the Einstein tensor of a given metric is a basic task in GR, so it's worth taking the time to work it through in detail for important cases like this one.

There are also computer programs that can help with the computation, such as Maxima.
 
  • Like
Likes   Reactions: BiaCarvalho
PeterDonis said:
If you can post specific places in the math where you're having trouble, we could try to help with that. Computing the Einstein tensor of a given metric is a basic task in GR, so it's worth taking the time to work it through in detail for important cases like this one.

There are also computer programs that can help with the computation, such as Maxima.
yes yes... I'm going to do it again and switch to latex, then I'll post it here later :D
 

Similar threads

Undergrad The quintessence as variable dark energy
  • · Replies 18 ·
Replies
18
Views
2K
High School History of Cosmology: 1915-1929 | Einstein, Hubble & GR
  • · Replies 19 ·
Replies
19
Views
3K
High School A question about which Cosmology theories are mainstream and how?
  • · Replies 5 ·
Replies
5
Views
2K
High School Big Bang as the Collapse of a Wave Function
  • · Replies 3 ·
Replies
3
Views
3K
Graduate Coefficient correlation between 2 cosmological probes
  • · Replies 2 ·
Replies
2
Views
1K
Undergrad Questions on the consequence of an evolving dark energy parameter
  • · Replies 1 ·
Replies
1
Views
2K
Undergrad Cosmological Redshift and Expansion
  • · Replies 20 ·
Replies
20
Views
2K
Undergrad Can a scalar field model account for the cosmic redshift?
  • · Replies 20 ·
Replies
20
Views
2K
High School Cosmological constant for the Universe's expansion
  • · Replies 5 ·
Replies
5
Views
3K
Undergrad 3 questions about a paper on density fluctuations in the Universe
  • · Replies 1 ·
Replies
1
Views
3K