An author can choose to post their paper on the arxiv or not, as they see fit (policies of the journal they wish to publish in aside). The papers on the arxiv a

An author can choose to post their paper on the arxiv or not, as they see fit (policies of the journal they wish to publish in aside). The papers on the arxiv are not peer reviewed, but many are of high quality. The idea is for researchers to have a faster mechanism than standard journals to share results.