*Title*: **Trace operators for homogeneous Sobolev spaces in infinite strip-like domains**

*Abstract*: Sobolev spaces are an indispensable tool in the modern theory of partial differential equations.
Trace embeddings show that functions in Sobolev spaces, which are a priori defined as elements of \(L^p\) and hence are only defined almost everywhere,
can actually be restricted to sufficiently regular hypersurfaces in a bounded way. Characterizing the resulting trace spaces and constructing bounded right inverses
(lifting results) then plays an essential role in using Sobolev spaces to study boundary-value problems in PDE.
The use of Sobolev spaces to study equations in unbounded, infinite-measure sets often requires employing homogeneous Sobolev seminorms,
in which only the highest-order derivatives are controlled in \(L^p\). In this setting, the classical trace results may fail
for certain choices of sets that appear naturally in PDE applications, such as infinite strip-like sets \( \mathbb{R}^{n-1}\times (0,b)
\subset \mathbb{R}^n\). In this talk we will survey the classical theory and then turn to recent developments in the homogeneous trace theory.
In particular, we will show that in strip-like sets the homogeneous trace spaces are characterized by a new type of fractional homogeneous Sobolev
regularity and an interaction between the traces on the different connected components of the boundary.

Smith Colloquium Fall 2018