TY - JOUR AB - We consider the ferromagnetic quantum Heisenberg model in one dimension, for any spin S≥1/2. We give upper and lower bounds on the free energy, proving that at low temperature it is asymptotically equal to the one of an ideal Bose gas of magnons, as predicted by the spin-wave approximation. The trial state used in the upper bound yields an analogous estimate also in the case of two spatial dimensions, which is believed to be sharp at low temperature. AU - Napiórkowski, Marcin M AU - Seiringer, Robert ID - 9256 IS - 2 JF - Letters in Mathematical Physics SN - 03779017 TI - Free energy asymptotics of the quantum Heisenberg spin chain VL - 111 ER -