Automorphism proof (graph theory)

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Homework Help Overview

The discussion revolves around a proof related to automorphisms in graph theory, specifically focusing on a transformation that needs to be shown as one-to-one, onto, and preserving adjacency. The original poster references a specific problem and provides some initial attempts at a solution.

Discussion Character

  • Exploratory, Conceptual clarification, Mathematical reasoning

Approaches and Questions Raised

  • Participants discuss the conditions under which the transformation is one-to-one and onto, with some exploring how adjacency is preserved. Questions are raised about the implications of coordinate equality in transformed vertices.

Discussion Status

Participants are actively engaging with the problem, questioning the assumptions about adjacency and exploring the implications of the transformation. Some guidance has been provided regarding the adjacency condition, but no consensus has been reached on the overall proof.

Contextual Notes

There is an indication that the original poster is uncertain about applying concepts like Hamming distance in this context, which may affect their approach to proving adjacency preservation.

TheMathNoob
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Homework Statement


The problem is attached and it's part A. There is no need to put problem 4 hence the problem is fully explained in the file attached

Homework Equations


Zk is mod k basically.

The Attempt at a Solution


I know that we have to prove that the transformation is onto,one to one and preserves adjacency.
It's one to one because
T(s1)=T(s2)
s1+v=s2+v
s1=s2

It's onto because
y=s+v
y-v=s
T(s)=T(y-v)=y-v+v=y
I am not quite sure how to show that it preserves adjacency because I can't apply the concept of hamming distance anymore.
 

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Two vertices are adjacent iff they have identical coordinates in all dimensions except for one.

Say ##U## and ##V## are adjacent because their coordinates are identical except for the ##j##th one.

For which, if any, of ##u\in\{1,2,...,n\}## are the ##u##th coordinates of ##T(U)## and ##T(V)## equal?
 
andrewkirk said:
Two vertices are adjacent iff they have identical coordinates in all dimensions except for one.

Say ##U## and ##V## are adjacent because their coordinates are identical except for the ##j##th one.

For which, if any, of ##u\in\{1,2,...,n\}## are the ##u##th coordinates of ##T(U)## and ##T(V)## equal?
Yes except for the jth coordinate?
 
Yes, and what does that tell us about whether T(U) and T(V) are adjacent?
 
andrewkirk said:
Yes, and what does that tell us about whether T(U) and T(V) are adjacent?
T(U) and T(V) are still adjacent because all their coordinates are the same except for the jth one.
 
andrewkirk said:
Yes, and what does that tell us about whether T(U) and T(V) are adjacent?
I had another problem. I would be glad if you take a look.
 

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