29.03.2013 Views

Lefschetz fibrations on adjoint orbits - PMA

Lefschetz fibrations on adjoint orbits - PMA

Lefschetz fibrations on adjoint orbits - PMA

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.

<str<strong>on</strong>g>Lefschetz</str<strong>on</strong>g> <str<strong>on</strong>g>fibrati<strong>on</strong>s</str<strong>on</strong>g> via Lie theory<br />

Notati<strong>on</strong>/definiti<strong>on</strong>:<br />

Let g be a complex semisimple Lie algebra and G a c<strong>on</strong>nected Lie<br />

group with Lie algebra g.<br />

The Cartan–Killing form of g,<br />

〈X , Y 〉 = tr (ad (X ) ad (Y )) ∈ C<br />

is symmetric and n<strong>on</strong>degenerate.<br />

Fix a Cartan subalgebra h ⊂ g. A root of h is a linear functi<strong>on</strong>al<br />

α : h → C, α = 0. Denote the set of all roots by Π.<br />

An element H ∈ h is regular if α (H) = 0 for all α ∈ Π.<br />

Elizabeth Gasparim <str<strong>on</strong>g>Lefschetz</str<strong>on</strong>g> <str<strong>on</strong>g>fibrati<strong>on</strong>s</str<strong>on</strong>g> <strong>on</strong> <strong>adjoint</strong> <strong>orbits</strong>

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

Saved successfully!

Ooh no, something went wrong!