Will my Web site's rating be affected by the fact that it can be reached using subdomains other than www?

My Web site is www.mathed.org, but it can be reached using anything in place of the www. I have seen people using hello.mathed.org and ricktoms.mathed.org. If these are the contents of links, will this affect my Google ranking? I have spoken to the host provider and they say that this is how they set up all their sites.