How to find articles containing specific keywords such as "cosmology" in several scientific databases?
ScienceDirect, Google Scholar, and other publisher or database services allow you to save a search and have any new items matching that be emailed to you (though it may not always be within a day - I vaguely recall that I usually knew about PLOS or ScienceDirect papers before I got the email - often via the Google Scholar alert! Still fairly timely, though.)

arXiv allows you to get a daily email with all new papers in a specific subject category. I don't believe it supports keyword searching for alerts - however, one of those categories is cosmology, so it may work fine for you.