Does the Product of Cycles Hold for Permutations?

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SUMMARY

The discussion focuses on proving that for a permutation P of a set, the equation P(i1i2...ir)B-1 = (P(i1)P(i2)...P(ir)) holds true. The solution approach involves demonstrating the validity of the equation for cycles, as any permutation can be expressed as a product of cycles. The user suggests evaluating P(i1,i2,...ir)P^(-1)P(i1) to establish the relationship between the mappings of the elements under the permutation.

PREREQUISITES
  • Understanding of permutation groups and cycle notation
  • Knowledge of group theory, specifically the properties of permutations
  • Familiarity with the concept of inverse functions in the context of permutations
  • Basic algebraic manipulation skills for evaluating expressions involving permutations
NEXT STEPS
  • Study the properties of permutation cycles in detail
  • Learn about the structure of symmetric groups and their applications
  • Explore the concept of conjugation in group theory
  • Investigate the relationship between permutations and their inverses
USEFUL FOR

This discussion is beneficial for students studying abstract algebra, particularly those focusing on group theory and permutations. It is also useful for educators looking to enhance their understanding of cycle notation and its implications in mathematical proofs.

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Homework Statement



Let P be a permutation of a set. Show that P(i1i2...ir)B-1 = (P(i1)P(i2)...P(ir))


Homework Equations



N/A

The Attempt at a Solution



Since P is a permutation, it can be written as the product of cycles. So I figured that showing that the above equation holds for cycles will be sufficient to show that it holds for all permutations.

Let C = (im1im2...imk) be a cycle and let D = (i1i2...ir). Then, for mk [tex]\neq[/tex] r,

imk[tex]\stackrel{C^{-1}}{\rightarrow}[/tex]imk-1[tex]\stackrel{D}{\rightarrow}[/tex]imk-1+1[tex]\stackrel{C}{\rightarrow}[/tex]imk+1

Let D` = (C(i1)C(i2)...C(ir)), then imk[tex]\stackrel{}{D`\rightarrow}[/tex]imk+1
 
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I accidentally made two threads. Just ignore this one.
 
Well, for example (P(i1)P(i2)...P(ir)) maps P(i1) to P(i2). You want to show P(i1,i2,...ir)P^(-1) does the same thing. Try it. Evaluate P(i1,i2,...ir)P^(-1)P(i1).
 

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