The Mathematics Department holds regular seminars on a variety of topics. Please see below for further details.

Seminars

Seminar Meeting Details Title & Abstract
Differential Equations Seminar
event
-
place
MSB 111
group
TBA

TBA

Speaker: Kiril Datchev (Purdue)
Differential Equations Seminar
event
-
place
MSB 111
group
TBA

TBA

Speaker: Jeremey Marzuola (UNC)
Algebra Seminar
event
-
place
MSB 110
group
TBA
Speaker: Takumi Murayama, Purdue University
Algebra Seminar
event
-
place
MSB 110
group
Cohomological Support Varieties Under Local Homomorphisms

Given a finitely generated module \(M\) over a noetherian local ring \(R\), one may assign to it a conical affine variety, called the cohomological support variety of \(M\) over \(R\). This theory was first developed by Luchezar Avramov for local complete intersection rings in 1989, and by the work of many has recently been extended to encompass all commutative noetherian local rings. Geometric properties of this variety encode important homological information about \(M\) as well as \(R\). In this talk I will discuss what cohomological support varieties are, why they are useful, and some recent work on how they behave when restricting along a local homomorphism.

Speaker: Ryan Watson, University of Nebraska Lincoln
Differential Equations Seminar
event
-
place
MSB 111
group
TBA
Speaker: Mengxuan Yang (Princeton)
Algebra Seminar
event
-
place
MSB 110 (note non-standard day)
TBA

Note the non-standard day

Speaker: Karl Schwede, University of Utah
Differential Equations Seminar
event
-
place
MSB 111
group
Nehari manifold analysis of Cahn-Hilliard energies with physical potentials

We study minimizers of Cahn-Hilliard energies under strong anchoring (Dirichlet) boundary conditions using a Nehari manifold approach with spectral analysis of the Dirichlet Laplacian.

For the de Gennes energy with quartic potential, we reveal bifurcation phenomena governed by the boundary value and transition layer thickness parameter. When the boundary value equals the phase average, and the parameter exceeds a critical threshold, the minimizer is unique and homogeneous; below this threshold, two symmetric minimizers emerge. Deviating boundary values restore uniqueness with asymmetric minimizers. We derive rigorous bounds for these solutions.

We extend this framework to the Flory-Huggins logarithmic potential, which models polymer blends and presents singular behavior at boundaries. Our analysis, supported by numerical simulations, reveals temperature-mediated bifurcations and demonstrates how the Nehari manifold technique provides a unified treatment of both functionals under strong anchoring conditions.

Speaker: Abba Ramadan (University of Alabama)
Algebra Seminar
event
-
place
MSB 110
Numerical Semigroups and the Bernstein-Sato Polynomial

The Bernstein-Sato Polynomial is a classical \(D\)-module invariant that has been used to measure the singularities of a hypersurface \(f\). In this talk we will review some of the classical theory before considering the Bernstein-Sato polynomial over a numerical semigroup ring \(R\). We will see that in this case the Bernstein-Sato polynomial detects not just of an element in \(R\) but of the ambient numerical semigroup ring itself. 

Speaker: Christopher Wong, University of Kansas
Differential Equations Seminar
event
-
place
MSB 111
group
Desingularization of nondegenerate rotating vortex patches

We analyze the space of steady rotating solutions to the two-dimensional incompressible Euler equations nearby vortex patch solutions satisfying a nondegeneracy condition. We address the question of desingularization and prove that such vortex patch states are the limit of rotating Euler solutions that are smooth to infinite order, have compact vorticity support, and respect dihedral symmetry. Our nondegeneracy condition is proved to be satisfied by Kirchhoff ellipses and along the local bifurcation curves emanating from the Rankine vortex. The construction, that is based on a local stream function formulation in a tubular neighborhood of the patch boundary, is a synthesis of analysis on thin domains, nonlinear a priori estimates, and Newton's method. Our techniques additionally allow us to construct nearby exotic families of singular rotating vortex patch-like solutions. This is joint work with Razvan-Octavian Radu.

Speaker: Noah Stevenson (Princeton)
Algebra Seminar
event
-
place
110 Math Science. Bldg.
Equivalence of Curve Singularities and Singularity degree

This talk is about joint work with I. Swanson.

\medbreak

A longstanding question in algebraic geometry is the classification of  reduced and 
irreducible local complete one--dimensional domains $R$ over an algebraically closed 
field $k$. It is known that such a ring is completely determined once it is known up 
to a "sufficiently high" power of its maximal ideal, where this sufficiently 
high power depends on the singularity degree $\delta$ of the ring.

In this talk we show that two curve singularities $(R, \mathfrak m)$ and $(R', \mathfrak m')$ 
are already isomorphic if there exists an isomorphishm 
$\varphi: R/ \mathfrak m^{j+1} \longrightarrow R'/ {\mathfrak m'}^{j+1}$ of 
$k$--algebras for some $j \geq 2 \delta +1$, and that the isomorphism may be chosen to agree with $\varphi 
\pmod{\mathfrak m^{j-2 \delta+1}}$. This strengthens a result of Hironaka, who obtained the
bound $3 \delta + 1$. 

Speaker: Reinhold Huebl, Purdue University