Question about existence of function with given derivatives - MathOverflow most recent 30 from http://mathoverflow.net2013-05-21T17:18:28Zhttp://mathoverflow.net/feeds/question/109131http://www.creativecommons.org/licenses/by-nc/2.5/rdfhttp://mathoverflow.net/questions/109131/question-about-existence-of-function-with-given-derivativesQuestion about existence of function with given derivativesuser 123452012-10-08T10:17:55Z2012-10-22T19:22:01Z
<p>Let $f_n : U \rightarrow \mathbb R$ be a given sequence of functions of class $C^\infty$ on open subsets $U \subset \mathbb R^n$. Does there exist a function $F:\mathbb R \times U \rightarrow \mathbb R$ of class $C^\infty$ such that
$$
\frac{\partial^n f}{\partial t^n}(0, x)=f_n(x)
$$
for $n=0,1,2,\ldots $ and all $x \in U ?$ </p>
http://mathoverflow.net/questions/109131/question-about-existence-of-function-with-given-derivatives/109148#109148Answer by Alexandre Eremenko for Question about existence of function with given derivativesAlexandre Eremenko2012-10-08T13:11:32Z2012-10-08T18:45:25Z<p>This is Theorem 1.2.6 in L. Hormander, Analysis of linear partial differential operators, vol. I.</p>