New posts in Group Rings

Let $x^2=y^2=1$ and $xy\neq yx$. There are $\binom{2n}{n}$ expressions of length $2n$ in $x$ and $y$ that are equal to $1$.

Why is the constant term of $(1+x+y+xy)^n$ equal to $\frac{1}{2}\binom{2n}{n}$？

The group ring of a ring.

Reference for Kaplansky's proof that in $\mathbb{C}[G]$, $ab=1$ implies $ba=1$

Using Dunwoody's results on cohomological dimension to learn about a von Neumann regular group ring

groupring morphisms and bialgebra

Torsion-freeness of two groups with 2 generators and 3 relators and Kaplansky Zero Divisor Conjecture