C n interval maps not Borel conjugate to any $C^{\infty}$ map

Proc. Amer. Math. Soc., 132, No. 4, 1091-1093, 2004.


We show that there exist interval maps which are not Borel conjugated to any $C^{\infty}$ map. These examples can be chosen to be topologically mixing and C n, for any finite, arbitrarily large n.

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