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3 votes
1 answer
244 views

Grothendieck group and an almost localization

Let $T$ be a small triangulated category and let $S\subset T$ be a full triangulated subcategory. We denote this embedding by $I: S\rightarrow T$. Let $F: T\rightarrow S$ be a triangulated functor ...
cellular's user avatar
  • 855
1 vote
1 answer
127 views

Example of triangulated category with vanishing $K_0$

Let $R$ be a ring, let $\operatorname{Perf}(R)$ the category of perfect modules over $R$. Suppose we have $E$ an perfect $R$-module (concentrated in degree $0$) such that its class $[E]\in K_0(R)$ is ...
cellular's user avatar
  • 855
1 vote
2 answers
306 views

How to compute the higher $K$-theory of a triangulated category having a semi-orthogonal decomposition?

I am starting to learn the $K$-theory of triangulated categories and is stuck with the following. Let $\mathcal{T}$ be a triangulated category having a semi-orthogonal decomposition $\langle \mathcal{...
Boris's user avatar
  • 639
4 votes
1 answer
410 views

Can higher G-theory of Noetherian schemes be computed by derived categories?

Recently I learned from the Stacks project that for every abelian category ${\mathcal A}$, there is a natural isomorphism $K_0({\mathcal A})\cong K_0(D^{b}(\mathcal A))$. When we set $\mathcal A$ to ...
Boris's user avatar
  • 639
2 votes
1 answer
331 views

Grothendieck group of triangulated categories

Let $A$ be a full triangulated subcategory of $B$, $u:A\rightarrow B$ the corresponding embedding. Let $f:B\rightarrow A$ be a triangulated functor satisfying: $f\circ u = id$ Let $b \in B $, if $f(b)...
LGO's user avatar
  • 169
2 votes
0 answers
178 views

construction of $K_0$-group and Karoubian completion

Let $A$ be a ring. The $K_0$ group of $A$ can be defined in most old fashioned way as the Grothendieck group of the set of isomorphism classes of its finitely generated projective $R$ modules, ...
user267839's user avatar
  • 6,028
23 votes
0 answers
647 views

Is this a model for $K$-theory of a triangulated category?

The recent question Complete the following sequence: point, triangle, octahedron, . . . in a dg-category reminded me of something I wanted to clarify long time ago; most likely this is now well known ...
მამუკა ჯიბლაძე's user avatar