I'm wondering if there are some known sources of open TCS problems? I'm a junior studying math/CS and would like to know of some accessible problems that I could start thinking about!
Thanks so much!
Here's a partial list of collections of open problems in TCS, broadly construed. Note that a collection of "major open problems" exists already on this site: http://cstheory.stackexchange.com/questions/174/major-unsolved-problems-in-theoretical-computer-science/251#251.
On sublinear algorithms: see Sublinear.info.
This is a (maintained) compilation of open problems, gathered from workshops and conferences on sublinear time algorithms (streaming, property testing, etc.)
On learning theory: see the open problems from COLT: 2013, 2014, 2015, 2016. COLT (Conference On Learning Theory) hosts a session dedicated to open problems, with a call for participation sent out every year:
The write-up of an open problem should include:
a clearly defined problem;
the motivation for studying the problem, with an argument why it is important and interesting;
the current state of this problem (including any known partial or conjectured solutions and relevant references).