Phantom Maps and Forgetable Maps
نویسنده
چکیده
In this note, we attack a question posed ten years ago by Tsukiyama about the injectivity of the socalled Forgetable map. We show that we can insert the Forgetable map in an exact sequence and that the problem can be reduced to the computation of the sequence which turns out unexpectedly to be related to the phantom map problem and the famous Halperin conjecture in rational homotopy theory.
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