Electronic Journal of Differential Equations, Vol. 2003(2003), No. 97, pp. 1-14. Title: The heat equation and the shrinking Authors: Masaki Kawagishi (Nihon University, Tokyo, Japan) Takesi Yamanaka (Nihon University, Tokyo, Japan) Abstract: This article concerns the Cauchy problem for the partial differential equation $$ \partial_1 u(t,x)-a\partial_2^2 u(t,x) =f(t,x,\partial_2^p u(\mu(t)t,x),\partial_2^q u(t,\nu(t)x))\,. $$ Here $t$ and $x$ are real variables, $p$ and $q$ are positive integers greater than 1, and the shrinking factors $\mu(t)$, $\nu(t)$ are positive-valued functions such that their suprema are less than 1. Submitted April 1, 2003. Published September 17, 2003. Math Subject Classifications: 35K05, 35K55, 35R10, 49K25. Key Words: Partial differential equation; heat equation; shrinking; delay; Gevrey