Abstract
Let n be a positive integer, and let A be a strongly commutative differential graded (DG) algebra over a commutative ring R. Assume that
-
(a)
\(B=A[X_1,\ldots ,X_n]\) is a polynomial extension of A, where \(X_1,\ldots ,X_n\) are variables of positive degrees; or
-
(b)
A is a divided power DG R-algebra and \(B=A \langle X_1,\ldots ,X_n \rangle \) is a free extension of A obtained by adjunction of variables \(X_1,\ldots ,X_n\) of positive degrees.
In this paper, we study naïve liftability of DG modules along the natural injection \(A\rightarrow B\) using the notions of diagonal ideals and homotopy limits. We prove that if N is a bounded below semifree DG B-module such that \({\text {Ext}}_B ^i (N, N)=0\) for all \(i\geqslant 1\), then N is naïvely liftable to A. This implies that N is a direct summand of a DG B-module that is liftable to A. Also, the relation between naïve liftability of DG modules and the Auslander-Reiten Conjecture has been described.
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Notes
Some authors use the cohomological notation for DG algebras. In such a case, A is described as \(A = \bigoplus _{n \leqslant 0} A ^n\), where \(A^{n} = A_{-n}\) and A is called non-positively graded.
“\(\mathrm {Mon}\)” is chosen for “monomial.”
Keller [19] calls these “DG modules that have property (P).”
The definition of diagonal ideals originates in scheme theory. In fact, if \(A \rightarrow B\) is a homomorphism of commutative rings, then the kernel of the natural mapping \(B \otimes _AB \rightarrow B\) is the defining ideal of the diagonal set in the Cartesian product \({\text {Spec}}B \times _{{\text {Spec}}A} {\text {Spec}}B\).
\(J^{[\ell ]}\) is just a notation for the \(\ell \)-th DG \(B^e\)-submodule of J in the sequence. It is not an \(\ell \)-th power of any kind.
In case that \(A \rightarrow B\) is a homomorphism of commutative rings, B is projective over A, and \(J/J^2\) is projective over B, then B is smooth over A in the sense of scheme theory. In this case, \(J/J^2 \cong \Omega _{B/A}\) is the module of Kähler differentials.
References
Araya, T., Yoshino, Y.: Remarks on a depth formula, a grade inequality and a conjecture of Auslander. Comm. Algebra 26(11), 3793–3806 (1998)
Auslander, M., Ding, S., Solberg, Ø.: Liftings and weak liftings of modules. J. Algebra 156, 273–397 (1993)
Auslander, M., Reiten, I.: On a generalized version of the Nakayama conjecture. Proc. Amer. Math. Soc. 52, 69–74 (1975)
Avramov, L.L.: Infinite free resolutions, Six lectures on commutative algebra (Bellaterra, 1996). Progr. Math., vol. 166, 1–118. Birkhäuser, Basel (1998)
Avramov, L.L., Buchweitz, R.-O.: Support varieties and cohomology over complete intersections. Invent. Math. 142(2), 285–318 (2000)
Avramov, L.L., Buchweitz, R.-O., Şega, L.M.: Extensions of a dualizing complex by its ring: commutative versions of a conjecture of Tachikawa. J. Pure Appl. Algebra 201(1–3), 218–239 (2005)
Avramov, L.L., Foxby, H.-B., Halperin, S.: Differential graded homological algebra (in preparation)
Avramov, L.L., Halperin, S.: Through the looking glass: a dictionary between rational homotopy theory and local algebra, Algebra, algebraic topology and their interactions (Stockholm, 1983), 1–27, Lecture Notes in Math., 1183, Springer, Berlin (1986)
Avramov, L.L., Iyengar, S.B., Nasseh, S., Sather-Wagataff, S.: Homology over trivial extensions of commutative DG algebras. Comm. Algebra 47, 2341–2356 (2019)
Avramov, L.L., Iyengar, S.B., Nasseh, S., Sather-Wagstaff, S.: Persistence of homology over commutative noetherian rings. Preprint at arxiv:2005.10808 (2020)
Bökstedt, M., Neeman, A.: Homotopy limits in triangulated categories. Compositio Math. 86(2), 209–234 (1993)
Christensen, L.W., Holm, H.: Algebras that satisfy Auslander’s condition on vanishing of cohomology. Math. Z. 265(1), 21–40 (2010)
Félix, Y., Halperin, S., Thomas, J.-C.: Rational homotopy theory, Graduate Texts in Mathematics, vol. 205. Springer-Verlag, New York (2001)
Gulliksen, T.H., Levin, G.: Homology of local rings, Queen’s Paper in Pure and Applied Mathematics, No. 20, Queen’s University. Kingston, Ontario, Canada (1969)
Huneke, C., Şega, L.M., Vraciu, A.N.: Vanishing of Ext and Tor over some Cohen-Macaulay local rings. Illinois J. Math. 48(1), 295–317 (2004)
Huneke, C., Jorgensen, D.A., Wiegand, R.: Vanishing theorems for complete intersections. J. Algebra 238(2), 684–702 (2001)
Jorgensen, D.A.: Finite projective dimension and the vanishing of \({\rm Ext}_R(M, M)\). Comm. Algebra 36(12), 4461–4471 (2008)
Jorgensen, D.A., Leuschke, G.J., Sather-Wagstaff, S.: Presentations of rings with non-trivial semidualizing modules. Collect. Math. 63(2), 165–180 (2012)
Keller, B.: Deriving DG categories. Ann. Sci. École Norm. Sup. (4) 27(1), 63–102 (1994)
Keller, B.: Derived categories and tilting, Handbook of tilting theory, 49–104, London Math. Soc. Lecture Note Ser., 332, Cambridge Univ. Press, Cambridge (2007)
Kontsevich, M., Soibelman, Y.: Notes on \(A^{\infty }\)-algebras, \(A^{\infty }\)-categories and non-commutative geometry. Homological mirror symmetry, 153–219, Lecture Notes in Phys., 757, Springer, Berlin (2009)
Nasseh, S., Ono, M., Yoshino, Y.: The theory of \(j\)-operators with application to (weak) liftings of DG modules. Preprint at arXiv:2011.15032 (2020)
Nasseh, S., Sather-Wagstaff, S.: Liftings and Quasi-Liftings of DG modules. J. Algebra 373, 162–182 (2013)
Nasseh, S., Sather-Wagstaff, S.: Extension groups for DG modules. Comm. Algebra 45, 4466–4476 (2017)
Nasseh, S., Sather-Wagstaff, S.: Vanishing of Ext and Tor over fiber products. Proc. Amer. Math. Soc. 145(11), 4661–4674 (2017)
Nasseh, S., Takahashi, R.: Local rings with quasi-decomposable maximal ideal. Math. Proc. Cambridge Philos. Soc. 168(2), 305–322 (2020)
Nasseh, S., Yoshino, Y.: On Ext-indices of ring extensions. J. Pure Appl. Algebra 213(7), 1216–1223 (2009)
Nasseh, S., Yoshino, Y.: Weak liftings of DG modules. J. Algebra 502, 233–248 (2018)
Ono, M., Yoshino, Y.: A lifting problem for DG modules. J. Algebra 566, 342–360 (2021)
Şega, L.M.: Vanishing of cohomology over Gorenstein rings of small codimension. Proc. Amer. Math. Soc. 131(8), 2313–2323 (2003)
Şega, L.M.: Self-tests for freeness over commutative Artinian rings. J. Pure Appl. Algebra 215(6), 1263–1269 (2011)
Shaul, L.: Smooth flat maps over commutative DG-rings. Math. Z. (to appear)
Tate, J.: Homology of Noetherian rings and local rings. Illinois J. Math. 1, 14–27 (1957)
Toën, B., Vezzosi, G.: Homotopical algebraic geometry. II. Geometric stacks and applications. Mem. Amer. Math. Soc. 193(902), x+224 pp (2008)
Yekutieli, A.: Derived categories, Cambridge Studies in Advanced Mathematics, Series Number 183, Cambridge University Press (2019)
Yoshino, Y.: The theory of L-complexes and weak liftings of complexes. J. Algebra 188(1), 144–183 (1997). (MR 98i:13024)
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We thank the referee for reading the paper and for helpful suggestions.
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Yuji Yoshino was supported by JSPS Kakenhi Grant 19K03448.
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Nasseh, S., Ono, M. & Yoshino, Y. Naïve liftings of DG modules. Math. Z. 301, 1191–1210 (2022). https://doi.org/10.1007/s00209-021-02951-z
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DOI: https://doi.org/10.1007/s00209-021-02951-z
Keywords
- DG algebra
- DG module
- DG quasi-smooth
- DG smooth
- Free extensions
- Lifting
- Naïve lifting
- Polynomial extensions
- Weak lifting