All Questions

Filter by
Sorted by
Tagged with
12 votes
1 answer
515 views

Embedding of a derived category into another derived category

I am considering the following two cases: Assume that there is an embedding: $D^b(\mathcal{A})\xrightarrow{\Phi} D^b(\mathbb{P}^2)$and the homological dimension of $\mathcal{A}$ is equal to $1$($\...
user41650's user avatar
  • 1,880
11 votes
0 answers
184 views

Quiver and relations for blocks of category $\mathcal{O}$

In Vybornov - Perverse sheaves, Koszul IC-modules, and the quiver for the category $\mathscr O$ an algorithm is presented to calculate quiver and relations for blocks of category $\mathcal{O}$ . ...
Mare's user avatar
  • 25.4k
8 votes
3 answers
1k views

Intuition behind the canonical projective resolution of a quiver representation

Let $Q$ be a finite acyclic quiver, and $X$ some representation of $Q$. For $i \in Q_0$ define the $kQ$-modules $P_i = kQe_i$, and $X(i) = e_i X$. The representation $X$ has a canonical projective ...
Mike Pierce's user avatar
  • 1,149
6 votes
2 answers
303 views

Path algebras are formally smooth

In Ginzburg's notes Lectures on Noncommutative Geometry, he claim that the path algebra of a quiver is formally smooth (See Section 19.2). I have two questions. First, how to show this claim and ...
Yining Zhang's user avatar
6 votes
2 answers
712 views

Auslander-Reiten theory for Gorenstein algebras

In the paper "Cohen-Macauley and Gorenstein artin algebras", Auslander and Reiten have a short section about Auslander-Reiten theory in Gorenstein algebras (I always assume we have an artin algebra ...
Mare's user avatar
  • 25.4k
6 votes
1 answer
465 views

Global dimension of quiver algebra

Given a representation-finite (finite dimensional over a field) quiver algebra of finite global dimension. Is $eAe$ isomorphic to the field for at least one primitive idempotent $e$? This is true for ...
Mare's user avatar
  • 25.4k
6 votes
0 answers
205 views

Classification of representation-finite algebras up to stable equivalence of Morita type

Assume $K$ is an algebraically closed field. I wanted to ask if there is a classification of the representation-finite $K$-algebras up to stable equivalence of Morita type (at least for some small ...
Mare's user avatar
  • 25.4k
3 votes
0 answers
95 views

Mutations in triangulated category and cluster algebra

Let $\mathcal{D}$ be an enhanced triangulated category (basically meaning that $\operatorname{Hom}$'s are complexes). There is the notion of mutation in an enhanced triangulated category: given a full ...
Estwald's user avatar
  • 945
2 votes
2 answers
135 views

Finding exceptional regular representations of $\tilde{D}_4$ efficiently

Let $A$ be the path algebra of the quiver $\tilde{D}_4$. I would like to find its exceptional regular representations with as little computation as possible. Of course, we can compute the whole ...
Sergey Guminov's user avatar
2 votes
1 answer
130 views

Rep infinite, but $\tau$-tilting finite

Let $A$ be a finite dimensional algebra over an algebraically closed field. I'm trying to better understand the difference between $A$ being representation infinite and $A$ being $\tau$-tilting ...
It'sMe's user avatar
  • 757
2 votes
0 answers
80 views

Example of a triangular string algebra that is rep infinite, but $\tau$-tilting finite

Let $A$ be a finite dimensional algebra over an algebraically closed field $\mathbb{K}$. Hence, $A$ can be realized as the path algebra of a bound quiver $(Q,I)$, where $I\subseteq\mathbb{K}Q$ is an ...
It'sMe's user avatar
  • 757
2 votes
0 answers
133 views

How to compute the derived functor of bounded derived categories of hereditary algebra?

Let $\Lambda$ be a finite dimensional algebra given by the quiver $$\cdot\leftarrow\cdot\leftarrow\cdot\rightarrow\cdot.$$ It can be view as an triangulated matrix algebra. $$\Lambda={A\ \ M\choose0\ ...
hgc's user avatar
  • 91
1 vote
1 answer
205 views

A result of Schofield in the case of quivers with relations

Let $Q$ be a quiver without oriented cycles. A result of Schofield says that, for dimension vectors $\alpha$ and $\beta$ of $Q$, $\beta\hookrightarrow\alpha$ iff $\operatorname{ext}(\beta, \alpha-\...
It'sMe's user avatar
  • 757
1 vote
1 answer
227 views

Bounded algebras of finite global dimension

Let $k$ be a field, $Q$ an acyclic finite quiver and $I$ an admissible ideal of $kQ$. I am looking for a reference for the fact that the bounded algebra $kQ/I$ has finite global dimension.
user52822's user avatar
1 vote
1 answer
275 views

finitely presented representations

Let Q=(V,E) be a direct graph where V is the set of all its vertices and E denotes the set of all its arrows. $X$ is called a representation of Q by modules if it is a functor from Q to R-Mod. i.e. $X(...
user38585's user avatar
  • 141
1 vote
0 answers
52 views

Is the Schofield semi invariant defined at $V/IV$?

Let $A=\mathbb{K}Q$ be the path algebra of an acyclic quiver $Q$ over an algebraically closed field $\mathbb{K}$, and $0\not=I\subset\mathbb{K}Q$ be an admissible ideal. Let $W$ be a left $A$-module ...
It'sMe's user avatar
  • 757
1 vote
0 answers
108 views

Prove that $B$ is a directing module

Let $A\cong\mathbb{K}Q/I$ be a finite dimensional, associative, basic $\mathbb{K}$ algebra, where $\mathbb{K}$ is algebraically closed and $Q$ is a finite Gabriel quiver on $n$ vertices and $I\...
It'sMe's user avatar
  • 757
1 vote
0 answers
75 views

Endomorphism ring of a cotilting module

Given a basic tilting or cotilting right module $T$ over an algebra $A$ given by quiver and relations, is there a "linear-algebra method" to decide whether $\operatorname{End}_A(T) \cong A?$ Here "...
Mare's user avatar
  • 25.4k
0 votes
0 answers
86 views

Connected components of $Q(\mathrm{s\tau-tilt}A)$

I'm reading about support $\tau$-tilting modules and their mutations. I'm trying to understand the mutation quiver. Let $A$ be a finite dimensional algebra over an algebraically closed field, which is ...
It'sMe's user avatar
  • 757