Green's function and the resistance across a Hypercube

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Homework Help Overview

The discussion revolves around calculating the resistance in a network represented by a hypercube in three dimensions and higher. The original poster expresses familiarity with solving similar problems in two dimensions but seeks guidance for extending this understanding to higher dimensions, particularly using Green's function.

Discussion Character

  • Exploratory, Assumption checking, Conceptual clarification

Approaches and Questions Raised

  • Participants explore the application of known methods from two-dimensional resistance networks to three dimensions. There is a discussion about the relevance of Green's function in this context, with some participants questioning whether it is necessary given their current understanding of resistance calculations using Kirchhoff's laws.

Discussion Status

The conversation is ongoing, with participants sharing insights and hints. One participant has derived a resistance value for the three-dimensional case but expresses uncertainty about the necessity of using Green's function. There are also inquiries about extending the problem to the fourth dimension and beyond, indicating a productive exploration of the topic.

Contextual Notes

Participants note the need to establish a general formula for the connections between vertices in higher dimensions, highlighting the complexity of the problem as it scales. There is an emphasis on understanding the patterns that emerge in the resistance network as dimensions increase.

Hamsi
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Homework Statement
I do know how to solve the resistance network problem in two dimensions. However, in this problem they want it in 3 dimensions and higher and I don't know how to do that
Relevant Equations
-
Homework Statement: I do know how to solve the resistance network problem in two dimensions. However, in this problem they want it in 3 dimensions and higher and I don't know how to do that
Homework Equations: -

In the picture you can see the solution to the two dimensional version
 

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Green's function??

Anyway, the hint is very useful.
Start by seeing how that works in 2D. We have a square, ABCD, say. From one corner, A, there are two adjacent links, to B and D. From an electrical perspective AB and AD are parallel.
At the next step there are another two, then we reach the target, C.
The trick is that you do not need to worry about how the first pair connect to the second. Suppose we were to connect B and D as well. By symmetry, no current would flow in BD.
Now try the same method in 3D.
 
Thank you for your response.

I think I understand the problem in 2D and now I think I also understand the problem in 3D. For 3D, I got th answer $$ (5/6 )R_0$$.

However, I got this answer by using basic things as kirkhoff and rules for resistances in parallel or serie. I did not use greens function. I feel like I should, since the homerwork hints towords it.

Also, I have no idea how to do quenstion b and c. There they ask about the 4th deminsion and higher. Can you maybe give me hint for thos
 
Hamsi said:
they ask about the 4th deminsion and higher
First, you need to find a general formula for the number of links that connect vertices at distance r from the starting corner to those at distance r+1 from it.
Write out those numbers for 1, 2 and 3 dimensions. In each case, the list of numbers will have a common factor n. If you factor that out, should see a familiar pattern.
 

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