Problem from A Beautiful Mind

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Discussion Overview

The discussion revolves around a mathematical problem presented in the movie "A Beautiful Mind," specifically concerning the dimensions of certain vector spaces related to deRham cohomology in the context of \(\mathbb{R}^3\) with a subset \(X\). Participants explore the implications of the problem and the significance of the variable \(X\).

Discussion Character

  • Technical explanation
  • Debate/contested
  • Mathematical reasoning

Main Points Raised

  • Some participants suggest that \(V/W\) represents the first deRham cohomology group of the space \(\mathbb{R}^3 \setminus X\), indicating that \(X\) is a subset of \(\mathbb{R}^3\).
  • One participant notes the inability to solve the problem without knowing what \(X\) is.
  • Another participant claims that \(\dim(V/W) = 8\) and connects this to an inverse cohomology problem involving finding a manifold with an 8-dimensional fundamental group.
  • Several participants clarify the notation used, specifically that \(\times\) refers to the vector cross-product and \(\nabla \times\) refers to the curl operator in vector calculus.
  • There is confusion regarding the meaning of \(X\) in the expression \(X \rightarrow \mathbb{R}^3\), with some participants attempting to clarify its significance.
  • Additional resources related to the Nash problem are shared, although their relevance to the current discussion is not explicitly stated.

Areas of Agreement / Disagreement

Participants express uncertainty regarding the definition of \(X\) and its implications for the problem. There is no consensus on the value of \(\dim(V/W)\), with differing claims about its dimensionality.

Contextual Notes

The discussion highlights the dependence on the definition of \(X\) and the implications this has for the mathematical problem being analyzed. Unresolved mathematical steps and assumptions about the nature of \(X\) are noted.

Dragonfall
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Problem from "A Beautiful Mind"

In the movie when he first walks into teach that ad cal class, this is the problem he wrote on the board (verbatim):

V=\{F:\mathbb{R}^3\backslash X\rightarrow \mathbb{R}^3:\nabla\times F=0\}

W=\{F=\nabla g\}

\dim (V/W)=?

What's X?
 
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V/W is the first deRham cohomology group of the space R^3\X, where X is presumably some subset of R^3.
 


Just finished reading the biog. A good read. Can't help with the above math though.
 


Can't solve it without X.
 


Dim(v/w) = 8 instead of question mark.

inverse cohomology problem to find a manifold M with a 8-dimensional fundamental group.
 


Dragonfall said:
What's X?

\times is the vector cross-product.

\nabla\times is the vector calculus "curl" operator.
 


AlephZero said:
\times is the vector cross-product.

In that case, what does \mathbb{R}^3 \slash \times signify?
 


Firstly the person is right in saying \times is the x but that is not what the person is referring to, they are asking what the X means in X\rightarrow \mathbb{R}^{3}. But I believe the person is right in saying it is the first deRham cohomology group.
 


Material on the Nash problem:

1) http://answers.yahoo.com/question/index?qid=20080501140727AAb2Ys1", Yahoo Answers

2) A beautiful mind http://www.math.harvard.edu/~huizenga/LECTURE35WS.PDF" .

3) http://www.math.harvard.edu/~knill/teaching/math21a/nash.pdf" , Spring 2004

4) "www.wfu.edu/~parslerj/math733/lecture%20notes%201-4.pdf"[/URL], Math 733: Vector Fields, Differential Forms, and Cohomology
[PLAIN]http://www.wfu.edu/~parslerj/math733/note.html" , R. Jason Parsley
 
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