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Francesco Polizzi
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Singularities Do singularities of plane curves deform independently?

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If $C\subset\mathbb{P}^2$ is an integral curve of degree $d$, do its singularities deform independently as we vary $C$ over degree $d$ curves? If not, what about in the case $C$ is a nodal curve or $C$ is a general nodal curve?

Edit: In other words, is the composition $H^0(C,N_{C/\mathbb{P}^2})={\rm Hom}(N_{C/\mathbb{P}^2}^\vee,\mathscr{O}_C)\rightarrow {\rm Ext}^1(\Omega_C,\mathscr{O}_C)\rightarrow Ext^1(\Omega_C,\mathscr{O}_C)$ surjective?

(If I did the reduction correctly, which is not a given, I think this is equivalent to the vector space $V=k[X,Y,Z]_d$ of degree $d$ homogenous polynomials surjecting onto the sheaf associated to the graded module $k[X,Y,Z]/(F,\partial_XF,\partial_YF,\partial_ZF)$, where $C=V(F)$.)

If $C\subset\mathbb{P}^2$ is an integral curve of degree $d$, do its singularities deform independently as we vary $C$ over degree $d$ curves? If not, what about in the case $C$ is a nodal curve or $C$ is a general nodal curve?

(If I did the reduction correctly, which is not a given, I think this is equivalent to the vector space $V=k[X,Y,Z]_d$ of degree $d$ homogenous polynomials surjecting onto the sheaf associated to the graded module $k[X,Y,Z]/(F,\partial_XF,\partial_YF,\partial_ZF)$, where $C=V(F)$.)

If $C\subset\mathbb{P}^2$ is an integral curve of degree $d$, do its singularities deform independently as we vary $C$ over degree $d$ curves? If not, what about in the case $C$ is a nodal curve or $C$ is a general nodal curve?

Edit: In other words, is the composition $H^0(C,N_{C/\mathbb{P}^2})={\rm Hom}(N_{C/\mathbb{P}^2}^\vee,\mathscr{O}_C)\rightarrow {\rm Ext}^1(\Omega_C,\mathscr{O}_C)\rightarrow Ext^1(\Omega_C,\mathscr{O}_C)$ surjective?

(If I did the reduction correctly, which is not a given, I think this is equivalent to the vector space $V=k[X,Y,Z]_d$ of degree $d$ homogenous polynomials surjecting onto the sheaf associated to the graded module $k[X,Y,Z]/(F,\partial_XF,\partial_YF,\partial_ZF)$, where $C=V(F)$.)

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