07.01.2015 Views

Permutation representations of finite simple groups: Orbits of cyclic ...

Permutation representations of finite simple groups: Orbits of cyclic ...

Permutation representations of finite simple groups: Orbits of cyclic ...

SHOW MORE
SHOW LESS

You also want an ePaper? Increase the reach of your titles

YUMPU automatically turns print PDFs into web optimized ePapers that Google loves.

Idea <strong>of</strong> the Pro<strong>of</strong><br />

A mixture <strong>of</strong> the two techniques already mentioned is needed:<br />

intersections <strong>of</strong> conjugacy classes <strong>of</strong> sub<strong>groups</strong> and embeddings<br />

<strong>of</strong> permutation modules.<br />

1. Embeddings: Let G be in L1, acting doubly transitively on<br />

the set Ω. Suppose that G also acts non-trivially on some other<br />

set ∆. Consider the corresponding F G-modules F Ω and F ∆.<br />

Let<br />

ϕ: F Ω → F ∆<br />

be a non-zero F G-homomorphism. Then its kernel can only be<br />

0, I or F Ω − I.

Hooray! Your file is uploaded and ready to be published.

Saved successfully!

Ooh no, something went wrong!