Time-dependent correlation functions of the classical one-dimensional XY model at infinite temperature

Computer calculations of the time-dependent spin and energy correlation functions of the classical one-dimensional XY model at infinite temperature are reported. Plots of 〈SzⁱSzⁱ(t)〉, 〈SzⁱSzⁱ⁺¹(t)〉, 〈εⁱεⁱ(t)〉, and (1/2)[〈SₓⁱSₓⁱ(t)〉+〈SyⁱSyⁱ(t)〉] out to times $Jt=9$ are given (εⁱ is the energy-density operator and J is the exchange integral). Comparison is made with the exact results for the spin-1/2 XY model. After an appropriate scaling of the exchange integral and normalization to the classical value at $t=0$ the values of the spin-1/2 functions are close to the values of their classical counterparts for times up to Jt≈4.