Are new domains indexed faster than old domains?

I bought an old domain to start a new blog but I feel it took a long time to get indexed (15 days) but for new pages with fresh content, they get indexed well. Could the slow index be a bad signal for SEO? or is it just because old domains get re-indexed slower? for next times I should buy new domains because new domains can be indexed faster old domains? some explanation?

Usually old domains with authority get indexed faster than brand new domains but if a domain is old with no authority or seo a new domain few months old with good seo(authority links) will get indexed faster than it

According to my experience, new domains are always be easy to get indexed than old domains. I don't know how it could happens but I would go with new domains for better SEO.

Old domains have some of factors like age, DA etc where depends on that domain name, it they all factors are positive response of Google, they easily indexed otherwise it's take some time of old domains.

Yes it may happen that Old domains may not rank faster in the Search Engines due to the authority factors. But you can make them indexed quickly by Pinging ur blog and Submitting it Directly into the webmasters tools.

When you say you bought an old domain, do you mean you bought one from a person/business/website that never got dropped/deleted/etc.?

Because if you bought one that was dropped/etc. and got it for registration fee then it's life basically starts out new again (for the most part) and it's considered a new domain for all intents and purposes. I buy dropped domains and have for a very long time (as well as new domains) and right after I get them I will slap up a temporary/coming soon page/site and they always get indexed right away, within less than an hour.

If you bought a domain before it was dropped/etc. then what was on the domain as far as website if anything can play a role in how fast it gets crawled again. If it was a highly inactive domain/site and you bought it, the SE's wouldn't just think it's not very active and won't crawl it that often.