Recognition: 2 theorem links
· Lean TheoremQuasi-Gorenstein morphisms of commutative local dg-algebras
Pith reviewed 2026-05-08 18:45 UTC · model grok-4.3
The pith
Quasi-Gorenstein morphisms of commutative local dg-algebras are characterized by a Gorenstein version of the virtually small property.
A machine-rendered reading of the paper's core claim, the machinery that carries it, and where it could break.
Core claim
We introduce quasi-Gorenstein morphisms of commutative local dg-algebras and use a Gorenstein version of the virtually small property to characterize them, a result which is new even for homomorphisms of local rings. In a different direction, we characterize exact sequences in a noetherian local ring in terms of quasi-Gorenstein morphisms involving Koszul complexes.
What carries the argument
The Gorenstein version of the virtually small property, which identifies exactly which morphisms qualify as quasi-Gorenstein.
If this is right
- Quasi-Gorenstein morphisms supply a uniform description of exact sequences in noetherian local rings via Koszul complexes.
- The characterization requires no extra conditions on the algebras or the base ring.
- The same criterion works for ordinary homomorphisms of local rings.
- New detection methods become available for Gorenstein properties of morphisms in the dg-setting.
Where Pith is reading between the lines
- The same style of argument could be tested on other homological properties such as Cohen-Macaulay behavior for dg-algebra morphisms.
- Concrete computations with low-dimensional Koszul complexes would provide explicit checks of the characterization.
- The notion may extend to invariants in derived categories that track Gorenstein conditions across base changes.
Load-bearing premise
The Gorenstein version of the virtually small property applies directly to morphisms of commutative local dg-algebras and supplies a complete characterization without further restrictions.
What would settle it
A morphism of commutative local dg-algebras that meets the quasi-Gorenstein definition yet fails the Gorenstein virtually small property, or the converse.
read the original abstract
We introduce quasi-Gorenstein morphisms of commutative local dg-algebras and use a Gorenstein version of the virtually small property to characterize them, a result which is new even for homomorphisms of local rings. In a different direction, we characterize exact sequences in a noetherian local ring, in the sense of Avramov, Henriques, and \c{S}ega, in terms of quasi-Gorenstein morphisms involving Koszul complexes.
Editorial analysis
A structured set of objections, weighed in public.
Referee Report
Summary. The paper introduces quasi-Gorenstein morphisms of commutative local dg-algebras and characterizes them via a Gorenstein analogue of the virtually small property; this characterization is asserted to be new even when restricted to ordinary homomorphisms of local rings. In a separate direction, exact sequences of modules over a noetherian local ring (in the sense of Avramov-Henriques-Šega) are characterized in terms of quasi-Gorenstein morphisms between Koszul complexes.
Significance. If the central claims hold, the work supplies a conceptual extension of Gorenstein homological algebra to the dg-setting and furnishes a new tool for detecting exact sequences. The use of the virtually-small property as a characterizing device is a clear strength, as it reduces the definition to a homological condition that is already known to be useful in the classical case. The Koszul-complex application provides a concrete link to existing literature on exact sequences and may prove useful for computations.
minor comments (2)
- The abstract and introduction would benefit from an explicit statement of the precise hypotheses on the base ring and on the differentials of the dg-algebras; without this, it is difficult to see at a glance whether the Gorenstein virtually-small property transfers without additional flatness or noetherian hypotheses.
- Notation for the Koszul complex and for the exact-sequence condition of Avramov-Henriques-Šega should be recalled or referenced in the statement of the second main theorem so that the reader does not need to consult external sources to parse the claim.
Simulated Author's Rebuttal
We thank the referee for the positive assessment of our work, including the recognition that the characterization via the Gorenstein virtually small property is new even for ordinary ring homomorphisms and that the Koszul-complex application provides a useful link to the literature on exact sequences. We appreciate the recommendation for minor revision.
Circularity Check
No significant circularity detected
full rationale
The paper defines quasi-Gorenstein morphisms of commutative local dg-algebras and invokes a Gorenstein version of the virtually small property to obtain a characterization, which is claimed to be new even for ordinary local ring homomorphisms. A second result expresses exact sequences (in the Avramov-Henriques-Šega sense) via quasi-Gorenstein morphisms of Koszul complexes. Neither step reduces by construction to a fitted parameter, a self-referential equation, or a load-bearing self-citation whose content is merely renamed; the central claims rest on independent definitions and transfer of an external property to the dg-algebra setting. The derivation chain is therefore self-contained against external benchmarks.
Axiom & Free-Parameter Ledger
Reference graph
Works this paper leans on
-
[1]
Avramov,Infinite free resolutions, Six lectures on commutative algebra (Bellaterra, 1996), Progr
Luchezar L. Avramov,Infinite free resolutions, Six lectures on commutative algebra (Bellaterra, 1996), Progr. Math., vol. 166, Birkh¨ auser, Basel, 1998, pp. 1–118. MR 1648664
1996
-
[2]
Avramov and Hans-Bjørn Foxby,Locally Gorenstein homomorphisms, Amer
Luchezar L. Avramov and Hans-Bjørn Foxby,Locally Gorenstein homomorphisms, Amer. J. Math.114 (1992), no. 5, 1007–1047. MR 1183530
1992
-
[3]
London Math
,Ring homomorphisms and finite Gorenstein dimension, Proc. London Math. Soc. (3)75(1997), no. 2, 241–270. MR 1455856
1997
-
[4]
Avramov, Inˆ es Bonacho Dos Anjos Henriques, and Liana M
Luchezar L. Avramov, Inˆ es Bonacho Dos Anjos Henriques, and Liana M. S ¸ega,Quasi-complete inter- section homomorphisms, Pure Appl. Math. Q.9(2013), no. 4, 579–612. MR 3263969
2013
-
[5]
Avramov, Srikanth B
Luchezar L. Avramov, Srikanth B. Iyengar, Saeed Nasseh, and Sean Sather-Wagstaff,Homology over trivial extensions of commutative DG algebras, Comm. Algebra47(2019), no. 6, 2341–2356. MR 3957101
2019
-
[6]
Z.309(2025), no
Isaac Bird, Liran Shaul, Prashanth Sridhar, and Jordan Williamson,Finitistic dimensions over com- mutative DG-rings, Math. Z.309(2025), no. 1, Paper No. 3, 29. MR 4827125
2025
-
[7]
Iyengar, Janina C
Benjamin Briggs, Srikanth B. Iyengar, Janina C. Letz, and Josh Pollitz,Locally complete intersec- tion maps and the proxy small property, Int. Math. Res. Not. IMRN (2022), no. 16, 12625–12652. MR 4466008
2022
-
[8]
39, Cambridge University Press, Cambridge, 1993
Winfried Bruns and J¨ urgen Herzog,Cohen-Macaulay rings, Cambridge Studies in Advanced Mathe- matics, vol. 39, Cambridge University Press, Cambridge, 1993. MR 1251956
1993
-
[9]
Buchsbaum and David Eisenbud,Algebra structures for finite free resolutions, and some structure theorems for ideals of codimension3, Amer
David A. Buchsbaum and David Eisenbud,Algebra structures for finite free resolutions, and some structure theorems for ideals of codimension3, Amer. J. Math.99(1977), no. 3, 447–485. MR 453723
1977
-
[10]
Lars Winther Christensen, Hans-Bjørn Foxby, and Henrik Holm,Derived category methods in commu- tative algebra, Springer Monographs in Mathematics, Springer Cham, 2024
2024
-
[11]
Algebra302(2006), no
Lars Winther Christensen, Anders Frankild, and Henrik Holm,On Gorenstein projective, injective and flat dimensions—a functorial description with applications, J. Algebra302(2006), no. 1, 231–279. MR 2236602
2006
-
[12]
Dibaei and Mohsen Gheibi,Sequence of exact zero-divisors,https://arxiv.org/abs/ 1112.2353
Mohammad T. Dibaei and Mohsen Gheibi,Sequence of exact zero-divisors,https://arxiv.org/abs/ 1112.2353
-
[13]
Dwyer, John P
William G. Dwyer, John P. C. Greenlees, and Srikanth B. Iyengar,Finiteness in derived categories of local rings, Comment. Math. Helv.81(2006), no. 2, 383–432. MR 2225632
2006
-
[14]
London Math
Anders Frankild, Srikanth Iyengar, and Peter Jørgensen,Dualizing differential graded modules and Gorenstein differential graded algebras, J. London Math. Soc. (2)68(2003), no. 2, 288–306. MR 1994683
2003
-
[15]
Math.135(2003), 327–353
Anders Frankild and Peter Jørgensen,Gorenstein differential graded algebras, Israel J. Math.135(2003), 327–353. MR 1997049
2003
-
[16]
and Jos´ e J
Antonio Garcia R. and Jos´ e J. M. Soto,Ascent and descent of Gorenstein property, Glasg. Math. J.46 (2004), no. 1, 205–210. MR 2034847
2004
-
[17]
Grayson and Michael E
Daniel R. Grayson and Michael E. Stillman,Macaulay2, a software system for research in algebraic geometry, Available athttp://www2.macaulay2.com
-
[18]
S ¸ega,Free resolutions over short Gorenstein local rings, Math
Inˆ es Bonacho Dos Anjos Henriques and Liana M. S ¸ega,Free resolutions over short Gorenstein local rings, Math. Z.267(2011), no. 3-4, 645–663. MR 2776052
2011
-
[19]
Jiangsheng Hu, Xiaoyan Yang, and Rongmin Zhu,G-dimensions for DG-modules over commutative DG-rings, Proc. Edinb. Math. Soc. (2)68(2025), no. 4, 1370–1389. MR 4973447
2025
-
[20]
Jorgensen,Some liftable cyclic modules, Comm
David A. Jorgensen,Some liftable cyclic modules, Comm. Algebra31(2003), no. 1, 493–504. MR 1969236
2003
-
[21]
Math.176(2003), no
Peter Jørgensen,Recognizing dualizing complexes, Fund. Math.176(2003), no. 3, 251–259. MR 1992822
2003
-
[22]
Kie lpi´ nski, D
R. Kie lpi´ nski, D. Simson, and A. Tyc,Exact sequences of pairs in commutative rings, Fund. Math.99 (1978), no. 2, 113–121. MR 480475
1978
-
[23]
Math.242(2021), no
Hiroyuki Minamoto,Homological identities and dualizing complexes of commutative differential graded algebras, Israel J. Math.242(2021), no. 1, 1–36. MR 4282074
2021
-
[24]
Math.245(2021), no
,Resolutions and homological dimensions of DG-modules, Israel J. Math.245(2021), no. 1, 409–454. MR 4357467
2021
-
[25]
Algebra515(2018), 102–156
Liran Shaul,Injective DG-modules over non-positive DG-rings, J. Algebra515(2018), 102–156. MR 3859962
2018
-
[26]
,The Cohen-Macaulay property in derived commutative algebra, Trans. Amer. Math. Soc.373 (2020), no. 9, 6095–6138. MR 4155173
2020
-
[27]
Math.386(2021), Paper No
,Koszul complexes over Cohen-Macaulay rings, Adv. Math.386(2021), Paper No. 107806, 35. MR 4266748 16 ZACHARY NASON, ANDREW J. SOTO LEVINS, AND RYAN WATSON
2021
-
[28]
Pure Appl
,Open loci results for commutative DG-rings, J. Pure Appl. Algebra226(2022), no. 5, Paper No. 106922, 11. MR 4327960
2022
-
[29]
Andrew J. Soto Levins and Prashanth Sridhar,Module-theoretic characterizations of Gorenstein mor- phisms, to appear in Mathematica Scandinavica,https://arxiv.org/abs/2502.16004
- [30]
-
[31]
183, Cambridge Univer- sity Press, Cambridge, 2020
,Derived categories, Cambridge Studies in Advanced Mathematics, vol. 183, Cambridge Univer- sity Press, Cambridge, 2020. MR 3971537 University of Nebraska Lincoln, NE 68588. U.S.A. Email address:znason2@huskers.unl.edu URL:https://zach-nason.github.io/ Texas Tech University, TX 79409. U.S.A. Email address:ansotole@ttu.edu URL:https://sites.google.com/view...
2020
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