Skip to main content
Commonmark migration
Source Link

Let $R$ be a $k$-algebra (not necessary commutative) and let $\mathbf{D}(R)$ be its derived category (right modules). I'm interested in the class of objects $V$ of $\mathbf{D}(R^{op})$ having the following property (P):

For any (infinite) product $\prod_{i\in I} M_{i}\in \mathbf{D}(R)$ the natural map $$ [\prod_{i\in I} M_{i}]\otimes^{L}_{R} V\longrightarrow \prod_{i\in I}[ M_{i}\otimes^{L}_{R} V]$$ is an isomorphism in $\mathbf{D}(k)$.

I have two questions.

  1. Does every perfect complex $V$ satisfy the property (P) ?

    Does every perfect complex $V$ satisfy the property (P) ?

  2. If the answer to the first question is positive, what is the biggest class of objects of $\mathbf{D}(R)$ having the property (P)? Does it have a name ?

  1. If the answer to the first question is positive, what is the biggest class of objects of $\mathbf{D}(R)$ having the property (P)? Does it have a name ?

PS: $R^{op}$ is the ring $R$ but with opposite multiplication. Thank you.

Ed.

Let $R$ be a $k$-algebra (not necessary commutative) and let $\mathbf{D}(R)$ be its derived category (right modules). I'm interested in the class of objects $V$ of $\mathbf{D}(R^{op})$ having the following property (P):

For any (infinite) product $\prod_{i\in I} M_{i}\in \mathbf{D}(R)$ the natural map $$ [\prod_{i\in I} M_{i}]\otimes^{L}_{R} V\longrightarrow \prod_{i\in I}[ M_{i}\otimes^{L}_{R} V]$$ is an isomorphism in $\mathbf{D}(k)$.

I have two questions.

  1. Does every perfect complex $V$ satisfy the property (P) ?
  1. If the answer to the first question is positive, what is the biggest class of objects of $\mathbf{D}(R)$ having the property (P)? Does it have a name ?

PS: $R^{op}$ is the ring $R$ but with opposite multiplication. Thank you.

Ed.

Let $R$ be a $k$-algebra (not necessary commutative) and let $\mathbf{D}(R)$ be its derived category (right modules). I'm interested in the class of objects $V$ of $\mathbf{D}(R^{op})$ having the following property (P):

For any (infinite) product $\prod_{i\in I} M_{i}\in \mathbf{D}(R)$ the natural map $$ [\prod_{i\in I} M_{i}]\otimes^{L}_{R} V\longrightarrow \prod_{i\in I}[ M_{i}\otimes^{L}_{R} V]$$ is an isomorphism in $\mathbf{D}(k)$.

I have two questions.

  1. Does every perfect complex $V$ satisfy the property (P) ?

  2. If the answer to the first question is positive, what is the biggest class of objects of $\mathbf{D}(R)$ having the property (P)? Does it have a name ?

PS: $R^{op}$ is the ring $R$ but with opposite multiplication. Thank you.

Ed.

Fixed some typos and cleaned up presentation
Source Link
Jeremy Rickard
  • 35.2k
  • 2
  • 110
  • 151

Let $R$ be a $k$-algebra (not necessary commutative) and let $\mathbf{D}(R)$ be its derived category (right modules). I'm interested onin the class of objects $V$ of $\mathbf{D}(R^{op})$ having the following property (P):

For any (infinite) product $\prod_{i\in I} M_{i}\in \mathbf{D}(R)$ the natural map $$ [\prod_{i\in I} M_{i}]\otimes^{L}_{R} V\longrightarrow \prod_{i\in I}[ M_{i}\otimes^{L}_{R} V]$$ is an isomorphism in $\mathbf{D}(k)$.

I have two questions.

  1. Does anyevery perfect complex $V$ verifiessatisfy the property (P) ?
  1. If the answer to the first question is positive, what is the biggest class of objects of $\mathbf{D}(R)$ having the property (P)? Does it have a name ?

PS: $R^{op}$ is the ring $R$ but with opposite multiplication. Thank you.

Ed.

Let $R$ be a $k$-algebra (not necessary commutative) and let $\mathbf{D}(R)$ be its derived category (right modules). I'm interested on the class of objects $V$ of $\mathbf{D}(R^{op})$ having the following property (P):

For any (infinite) product $\prod_{i\in I} M_{i}\in \mathbf{D}(R)$ the natural map $$ [\prod_{i\in I} M_{i}]\otimes^{L}_{R} V\longrightarrow \prod_{i\in I}[ M_{i}\otimes^{L}_{R} V]$$ is an isomorphism in $\mathbf{D}(k)$.

I have two questions.

  1. Does any perfect complex $V$ verifies the property (P) ?
  1. If the answer to the first question is positive, what is the biggest class of objects of $\mathbf{D}(R)$ having the property (P)? Does it have a name ?

PS: $R^{op}$ is the ring $R$ but with opposite multiplication. Thank you.

Ed.

Let $R$ be a $k$-algebra (not necessary commutative) and let $\mathbf{D}(R)$ be its derived category (right modules). I'm interested in the class of objects $V$ of $\mathbf{D}(R^{op})$ having the following property (P):

For any (infinite) product $\prod_{i\in I} M_{i}\in \mathbf{D}(R)$ the natural map $$ [\prod_{i\in I} M_{i}]\otimes^{L}_{R} V\longrightarrow \prod_{i\in I}[ M_{i}\otimes^{L}_{R} V]$$ is an isomorphism in $\mathbf{D}(k)$.

I have two questions.

  1. Does every perfect complex $V$ satisfy the property (P) ?
  1. If the answer to the first question is positive, what is the biggest class of objects of $\mathbf{D}(R)$ having the property (P)? Does it have a name ?

PS: $R^{op}$ is the ring $R$ but with opposite multiplication. Thank you.

Ed.

Intercahging Interchanging the tensor product with infinite product

Let $R$ be a $k$-algebra (nonnot necessary commutative) and let $\mathbf{D}(R)$ be its derived category (right modules). I'm interested on the class of objects $V$ of $\mathbf{D}(R^{op})$ having the following property (P):

For any (infinite) product $\prod_{i\in I} M_{i}\in \mathbf{D}(R)$ the natural map $$ [\prod_{i\in I} M_{i}]\otimes^{L}_{R} V\longrightarrow \prod_{i\in I}[ M_{i}\otimes^{L}_{R} V]$$ is an isomorphism in $\mathbf{D}(k)$. 

I have two questions.

  1. Does any perfect complex $V$ verifies the property (P) ?

  2. If the answer to the first question is positive, what is the biggest class of objects of $\mathbf{D}(R)$ having the property (P)? Does it have a name ?

  1. Does any perfect complex $V$ verifies the property (P) ?
  1. If the answer to the first question is positive, what is the biggest class of objects of $\mathbf{D}(R)$ having the property (P)? Does it have a name ?

PS: $R^{op}$ is the ring $R$ but with opposite multiplication. Thank you.

Ed.

Intercahging the tensor product with infinite product

Let $R$ be a $k$-algebra (non necessary commutative) and let $\mathbf{D}(R)$ be its derived category (right modules). I'm interested on the class of objects $V$ of $\mathbf{D}(R^{op})$ having the following property (P):

For any (infinite) product $\prod_{i\in I} M_{i}\in \mathbf{D}(R)$ the natural map $$ [\prod_{i\in I} M_{i}]\otimes^{L}_{R} V\longrightarrow \prod_{i\in I}[ M_{i}\otimes^{L}_{R} V]$$ is an isomorphism in $\mathbf{D}(k)$. I have two questions.

  1. Does any perfect complex $V$ verifies the property (P) ?

  2. If the answer to the first question is positive, what is the biggest class of objects of $\mathbf{D}(R)$ having the property (P)? Does it have a name ?

PS: $R^{op}$ is the ring $R$ but with opposite multiplication. Thank you.

Ed.

Interchanging the tensor product with infinite product

Let $R$ be a $k$-algebra (not necessary commutative) and let $\mathbf{D}(R)$ be its derived category (right modules). I'm interested on the class of objects $V$ of $\mathbf{D}(R^{op})$ having the following property (P):

For any (infinite) product $\prod_{i\in I} M_{i}\in \mathbf{D}(R)$ the natural map $$ [\prod_{i\in I} M_{i}]\otimes^{L}_{R} V\longrightarrow \prod_{i\in I}[ M_{i}\otimes^{L}_{R} V]$$ is an isomorphism in $\mathbf{D}(k)$. 

I have two questions.

  1. Does any perfect complex $V$ verifies the property (P) ?
  1. If the answer to the first question is positive, what is the biggest class of objects of $\mathbf{D}(R)$ having the property (P)? Does it have a name ?

PS: $R^{op}$ is the ring $R$ but with opposite multiplication. Thank you.

Ed.

Source Link
John-Ed
  • 117
  • 4
Loading