Skip to main content

All Questions

Filter by
Sorted by
Tagged with
0 votes
0 answers
128 views

Coxeter matrix of Dyck path

I am trying to understand Gjergji Zaimi's answer in What are the periodic Dyck paths?. In the third paragraph he claims that Next, we define the matrix $X_D$ similarly to the Cartan matrix except we ...
AlgebraicPhantom's user avatar
2 votes
0 answers
58 views

Relationship between the homology of two types of tensor products of $\mathbb{Z}/ 2 \mathbb{Z}$-graded objects?

Let's consider a $2$-periodic complex $F$ of free $R$-modules, which is just a $\mathbb{Z} / 2 \mathbb{Z}$-graded complex $$F_1 \xrightarrow{d_1} F_0 \xrightarrow{d_0} F_1$$ (really the arrow $d_0$ ...
Rellek's user avatar
  • 553
3 votes
0 answers
85 views

Exterior powers of the Cartan matrix and Dyck paths

(This question can be formulated purely combinatorially in terms of Dyck paths, which is done in the second part of the question. But I am more interested whether this can be explained by some sort of ...
Mare's user avatar
  • 26.5k
3 votes
0 answers
327 views

Homology $H_{\ast}(T, V)$

Let $A$ be a local domain. We let $T=T(A) $ be the subgroup of $\mathrm{SL}_{2}$ consisting of diagonal matrices and $V$ be the subgroup of unital matrices of $\mathrm{SL}_{2}$; i.e. $V:=\left\{\left( ...
Liddo's user avatar
  • 259
15 votes
2 answers
850 views

What are the periodic Dyck paths?

I changed the thread completely so that everything is now elementary linear algebra. A Dyck path of length $n$ is a list of positive integers $[c_1,c_2,...,c_n]$ with $c_i -1 \leq c_{i+1}$ for all $i$...
Mare's user avatar
  • 26.5k
5 votes
1 answer
702 views

Direct limits of a matrix and its transpose

Let $A \in M_n(\mathbb Z)$ and $A^T$ denote the transpose of $A$. Define the direct limits $$H_1 = \mathrm{colim} (\mathbb Z^n \xrightarrow{A} \mathbb Z^n \xrightarrow{A} \mathbb Z^n \xrightarrow{A} \...
Toke Nørgård-Sørensen's user avatar
3 votes
0 answers
319 views

a generalization of the annihilator of cokernel ideal (some new invariants of modules?) [closed]

Let $R$ be a (commutative, associative, unital) ring, consider a homomorphism of some (finitely generated) free $R$-modules $E\stackrel{A}{\rightarrow}F$. Say $rank(F)=m$. The basic invariants of $A$ ...
Dmitry Kerner's user avatar