In the representation theory of finite-dimensional algebras A over a field, the classification of 2-term (pre)silting complexes is an important problem. One of the useful tool is the g-vector cones associated to the 2-term presilting complexes in the real Grothendieck group K0(proj A) R := K0(proj A) ⊗ Z R. The aim of this paper is to study the complement NR of the union Cone of all g-vector cones, which we call the non-rigid region. By the work of Iyama and us, NR is determined by 2-term presilting complexes and a certain closed subset R0 ⊂ K0(proj A) R , which is called the purely non-rigid region. In this paper, we give an explicit description of R0 for complete special biserial algebras in terms of a finite set of maximal nonzero paths in the Gabriel quiver of A. We also prove that NR has some kind of fractal property and that NR is contained in a union of countably many hyperplanes of codimension one. Thus, any complete special biserial algebra is g-tame, that is, Cone is dense in K0(proj A) R .
Contents1. Introduction 1 2. Basic properties of complete special biserial algebras 5 3. Preliminary on silting theory and canonical decompositions 12 4. τ -Tilting reduction 21 5. Descriptions of the non-rigid regions 28 6. Applications 42 Funding 48 Acknowledgment 48 References 49