View Proposal #298

If this proposal belongs to you, you are authorized to update it. Use the menu on the right.

ID298
First NameLuke
Last NameSerafin
InstitutionCoe College
Speaker Categoryundergraduate student
Title of TalkExplicit Constructions of Functions whose Graphs are Dense in The Plane
AbstractA set D is dense in the plane if and only if every open ball in the plane contains an element of D. We prove that there exists a function f from the real line R to itself whose graph is dense in the plane by explicitly constructing it using a partition of the rationals into countably many subsets dense in R. We then use this method of construction to prove that there are 2^(2^\aleph_0) functions whose graphs are dense in the plane, and that there exists a function f: R ->R such that f(U) = R for every non-empty open set U in R.
Subject area(s)
Suitable for undergraduates?Yes
Day Preference
Computer Needed?
Bringing a laptop?Y
Overhead Needed?
Software requests
Special Needs
Date Submitted10/17/2010
Year2010