Searcharxiv⌕ Search

arXiv · 0704.1249

Cluster tilting for one-dimensional hypersurface singularities

Abstract

In this article we study Cohen-Macaulay modules over one-dimensional hypersurface singularities and the relationship with the representation theory of associative algebras using methods of cluster tilting theory. We give a criterion for existence of cluster tilting objects and their complete description by homological methods, using higher almost split sequences and results from birational geometry. We obtain a large class of 2-CY tilted algebras which are finite dimensional symmetric and satisfy $τ^2=\id$. In particular, we compute 2-CY tilted algebras for simple and minimally elliptic curve singularities.

Explore related subjects

Keep this discovery

Explore connections, maps & timelines

BibTeXRIS

Igor Burban, Osamu Iyama, Bernhard Keller, Idun Reiten. 2007-10-01. Cluster tilting for one-dimensional hypersurface singularities. https://arxiv.org/abs/0704.1249

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related papers

Mutation of τ-exceptional pairs and sequences

We introduce a notion of mutation for $τ$-exceptional sequences of modules over arbitrary finite dimensional algebras. For hereditary algebras, we show that this coincides with the classical mutation of exceptional sequences. For rank two algebras, we show that mutation of $τ$-exceptional sequences is transitive if and only if mutation of support $τ$-tilting modules in the sense of Adachi-Iyama-Reiten is transitive.

math.RT↗

Stability of plethysm coefficients and modified polynomial induction

Let $h_n$ denote the complete homogeneous symmetric function of degree $n$, $s_ν$ the Schur function indexed by a partition $ν$, and $\langle\cdot,\cdot\rangle$ the Hall inner product. The plethysm coefficient $\langle h_n[h_m], s_ν\rangle$ is the multiplicity of the Weyl module $W_ν(\mathbb{C}^N)$ in $\mathrm{Sym}^n(\mathrm{Sym}^m(\mathbb{C}^N))$ whenever $ν$ has at most $N$ parts. For a partition $λ$, let $λ[mn]=(mn-|λ|,λ_1,λ_2,\dots)$. Bowman and Paget proved that $\langle h_n[h_m], s_{λ[mn]}\rangle$ is independent of $m$ and $n$ once $m,n\ge|λ|$. We prove that this coefficient is already constant for $m\geλ_1$ and $n\ge\lfloor(|λ|+λ_1)/2\rfloor$, and that its stable value equals $\langle s_λ, H[H-1-h_1]\rangle$, where $H=\sum_{i\ge0}h_i$; the proof uses the skewing operators adjoint to multiplication by complete homogeneous symmetric functions. We give a short new proof of the Bowman-Paget theorem based on stability of vector-partition functions, which count the ways of writing a vector of non-negative integers as an unordered sum of non-zero such vectors (its parts). Using a Vandermonde-type determinantal identity, we deduce that the stable value is a signed sum of numbers of vector partitions all of whose parts have entries summing to at least 2. The same method gives a short proof of Brion's stability theorem. We show that the stable value equals the multiplicity of $W_λ(\mathbb{C}^k)$, where $k=\lfloor|λ|/2\rfloor$, in an explicit representation of $GL_k(\mathbb{C})$ independent of $m$ and $n$, obtained by modifying the polynomial induction of Narayanan, Paul, Prasad and Srivastava. Finally, we prove an explicit positive formula for the stable value, which counts the number of lattice points in a polytope, when $λ_1\le 4$.

math.RT↗

A Counterexample To The TF-cone Conjecture

The TF-cone conjecture of Asai and Iyama predicts that the TF equivalence class of an integral $g$-vector is the open cone generated by the canonical summands of all its positive multiples. We give a counterexample to this conjecture. For the tensor product of the three-arrow Kronecker algebra with the path algebra of $s\to t$, a vector $w$ has a two-dimensional TF equivalence class, whereas every positive integral multiple $mw$ is generically indecomposable. The cone generated by these canonical summands is therefore a single ray. The same example disproves the relative-interior version proposed by Haerizadeh and Yassemi.

math.RT↗