How do you do that specifies (page 34) that a mage could become invisible by using a Forces 2 effect. I would like to know if it is possible (and better if referenced in any source) to use Correspondence to somehow fold the space around the mage (instead of bending the light rays as you would do with Forces) to become invisible.
You'll Need Forces Anyway
Correspondence normally cannot be selective. You can bend space with Correspondence 4, but then you'll bend it for everything - light, bullets, sounds etc. To bend it selectively (even with a lower level, either Correspondence 2 or 3 can be argued for), you need a Conjunctional Effect which also includes at least Forces 2. So no, you cannot turn invisible by Correspondence alone.