Stack Exchange network consists of 183 Q&A communities including Stack Overflow, the largest, most trusted online community for developers to learn, share their knowledge, and build their careers.
@YCor Thank you for your answer, I will be pleased if you give me a reference for this result. On other hand, in the paper 'HOMOGENEOUS SPACETIMES OF ZERO CURVATURE' in PROCEEDINGS OF THE AMERICAN MATHEMATICALSOCIETY Volume 107, Number 3, November 1989, to prove the corollary 3.6 the authors affirm that a simply connected Lie group homeomorphic to $R^n$ is solvable. Does that mean that their proof is false?
