Dominican symbolism help?

[psocoptera]

Can anyone tell me what is up with these letters? AE with a superimposed V and m with a superimposed... lambda? a compass? This is a photo of a small side chapel containing the tomb of Thomas Aquinas in the Church of the Jacobins in Toulouse, and that choice of decoration clearly means something.

Comments

[carnap.livejournal.com]

Beats the heck out of me. Alpha (capitalized or not) is a traditional Christian symbol (God's role as beginning) but I don't know about sigma, and the lowercase m doesn't correspond to any Greek letter. It looks more like an upside-down omega to me, and omega's another traditional Christian symbol, but I don't have any idea why it would be upside-down. And what the v and lambda(?) are doing there I have no idea.