(5) Let G be an arbitrary group. (a) Prove that the formula g*a = ga defines an action of G on itself which is faithful: for any g ≤ G, if g ⋆ a = a for all a EG, then g = 1. (b) Prove that the formula g*a = gag 1 defines an action of G on itself. (c) Find a group G for which the action defined in (b) is not faithful.

Advanced Engineering Mathematics
10th Edition
ISBN:9780470458365
Author:Erwin Kreyszig
Publisher:Erwin Kreyszig
Chapter2: Second-order Linear Odes
Section: Chapter Questions
Problem 1RQ
icon
Related questions
Question

Abstract Algebra

(5) Let \( G \) be an arbitrary group.
   
(a) Prove that the formula 

\[
g \star a = ga
\]

defines an action of \( G \) on itself which is faithful: for any \( g \in G \), if \( g \star a = a \) for all \( a \in G \), then \( g = 1 \).

(b) Prove that the formula 

\[
g \star a = g a g^{-1}
\]

defines an action of \( G \) on itself.

(c) Find a group \( G \) for which the action defined in (b) is not faithful.
Transcribed Image Text:(5) Let \( G \) be an arbitrary group. (a) Prove that the formula \[ g \star a = ga \] defines an action of \( G \) on itself which is faithful: for any \( g \in G \), if \( g \star a = a \) for all \( a \in G \), then \( g = 1 \). (b) Prove that the formula \[ g \star a = g a g^{-1} \] defines an action of \( G \) on itself. (c) Find a group \( G \) for which the action defined in (b) is not faithful.
Expert Solution
steps

Step by step

Solved in 3 steps with 3 images

Blurred answer
Recommended textbooks for you
Advanced Engineering Mathematics
Advanced Engineering Mathematics
Advanced Math
ISBN:
9780470458365
Author:
Erwin Kreyszig
Publisher:
Wiley, John & Sons, Incorporated
Numerical Methods for Engineers
Numerical Methods for Engineers
Advanced Math
ISBN:
9780073397924
Author:
Steven C. Chapra Dr., Raymond P. Canale
Publisher:
McGraw-Hill Education
Introductory Mathematics for Engineering Applicat…
Introductory Mathematics for Engineering Applicat…
Advanced Math
ISBN:
9781118141809
Author:
Nathan Klingbeil
Publisher:
WILEY
Mathematics For Machine Technology
Mathematics For Machine Technology
Advanced Math
ISBN:
9781337798310
Author:
Peterson, John.
Publisher:
Cengage Learning,
Basic Technical Mathematics
Basic Technical Mathematics
Advanced Math
ISBN:
9780134437705
Author:
Washington
Publisher:
PEARSON
Topology
Topology
Advanced Math
ISBN:
9780134689517
Author:
Munkres, James R.
Publisher:
Pearson,