论文标题

在相对背景下的完整合并对的明确自偶型结构

An explicit self-dual construction of complete cotorsion pairs in the relative context

论文作者

Positselski, Leonid

论文摘要

令$ r \ to $为联想环的同态,让$(\ Mathcal f,\ Mathcal c)$是$ \ r \ mathsf {-mod} $中的遗传完整的cotorsion对。令$(\ Mathcal f_a,\ Mathcal C_A)$为$ a \ Mathsf {-mod} $中的CotorSion对,其中$ \ Mathcal f_a $是所有左$ a $ a $ a $ r $ -modules属于$ \ mathcal f $的$ a $ -mmodules的类。假设每个左$ r $ -MODULE的$ \ MATHCAL F $分辨率是有限的,并且$ \ MATHCAL F $由Coinduction Founctor $ \ opperatorname {hom} _r(a, - )$保留,我们显示了$ \ \ \ \ \ \ \ nathcal c_a $ by the triptire tirect tirect tirect yect y y Mathcal co_a co)co)$ -OD $ -OD $ -OD $ -MOD( $ a $ - 模块从$ r $ - 模块造成的$ \ Mathcal c $。假设类$ \ Mathcal f $在可数产品下关闭,并由函数$ \ permatatOrname {hom} _r(a, - - )$保留,我们证明$ \ nathcal c_a $是$ a $ a $ cofile cofter $ a $ cofile cof $ cof $ cof $ coful cof $ coful cof $ cof的$ coful coful cof的$ rys $ ry的所有直接总和。自然数索引的降低过滤。一个组合结果,基于以下假设:从$ \ Mathcal F $中的模块的可数产品具有有限的$ \ Mathcal F $分辨率尺寸,该尺寸由$ k $界定,涉及由序数$ω+k $索引的共滤。双重结果也可以得出,可以通过相同的技术回到作者关于半无限同源代数Arxiv的专着:0708.3398。此外,我们讨论了$ n $ cotilting和$ n $ tISTING COTORSION对,为此,我们使用合适的Bongartz-Ringel Lemma版本获得了更好的结果。作为本文主要结果的例证,我们考虑了与弯曲的DG模型相互矛盾和编码类别相关的某些合并对。

Let $R\to A$ be a homomorphism of associative rings, and let $(\mathcal F,\mathcal C)$ be a hereditary complete cotorsion pair in $R\mathsf{-Mod}$. Let $(\mathcal F_A,\mathcal C_A)$ be the cotorsion pair in $A\mathsf{-Mod}$ in which $\mathcal F_A$ is the class of all left $A$-modules whose underlying $R$-modules belong to $\mathcal F$. Assuming that the $\mathcal F$-resolution dimension of every left $R$-module is finite and the class $\mathcal F$ is preserved by the coinduction functor $\operatorname{Hom}_R(A,-)$, we show that $\mathcal C_A$ is the class of all direct summands of left $A$-modules finitely (co)filtered by $A$-modules coinduced from $R$-modules from $\mathcal C$. Assuming that the class $\mathcal F$ is closed under countable products and preserved by the functor $\operatorname{Hom}_R(A,-)$, we prove that $\mathcal C_A$ is the class of all direct summands of left $A$-modules cofiltered by $A$-modules coinduced from $R$-modules from $\mathcal C$, with the decreasing filtration indexed by the natural numbers. A combined result, based on the assumption that countable products of modules from $\mathcal F$ have finite $\mathcal F$-resolution dimension bounded by $k$, involves cofiltrations indexed by the ordinal $ω+k$. The dual results also hold, provable by the same technique going back to the author's monograph on semi-infinite homological algebra arXiv:0708.3398. In addition, we discuss the $n$-cotilting and $n$-tilting cotorsion pairs, for which we obtain better results using a suitable version of a classical Bongartz-Ringel lemma. As an illustration of the main results of the paper, we consider certain cotorsion pairs related to the contraderived and coderived categories of curved DG-modules.

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