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Jun 28, 2015 at 22:34 comment added Jason Starr @DavidTreumann Some non-Cohen-Macaulay ideals deform to Cohen-Macaulay ideals. I am not saying anything about the ideals that can or cannot be obtained by deforming your ideal. I am simply mentioning that your ideal is not Cohen-Macaulay, which is too bad, because otherwise it would be much easier to study your problem.
Jun 28, 2015 at 20:59 comment added David Treumann Thanks Will and Jason. Jason, can a non-CM ideal be flatly deformed to a CM ideal? Or are you telling me that this variety has no smooth deformations at all!
Jun 28, 2015 at 18:18 comment added Jason Starr That ideal is, unfortunately, not Cohen-Macaulay (at least if I did my computation correctly). It has an embedded prime $\langle y,u,v\rangle$. That is unfortunate: if it were Cohen-Macaulay, then the Hilbert-Burch-(Schaps) Theorem would describe all flat deformations via variation of a matrix of polynomials (in particular, infinitesimal deformations would always be unobstructed).
Jun 28, 2015 at 3:33 history edited David Treumann CC BY-SA 3.0
wrong equations
Jun 28, 2015 at 3:22 comment added Will Sawin One might try to embed the ideal in the simplest way in $\mathbb P^4$, compute its Hilbert polynomial, and try to understand the appropriate Hilbert scheme.
Jun 28, 2015 at 2:44 history edited Allen Knutson CC BY-SA 3.0
made title more specific to the question
S Jun 28, 2015 at 2:44 history suggested Michael Albanese CC BY-SA 3.0
Put math in MathJax.
Jun 28, 2015 at 2:26 review Suggested edits
S Jun 28, 2015 at 2:44
Jun 28, 2015 at 1:50 history asked David Treumann CC BY-SA 3.0