<p>For a smooth and quasi-projective variety <i>X</i> of dimension <InlineEquation ID="IEq1"> <EquationSource Format="TEX">\(d \ge 5\)</EquationSource> <EquationSource Format="MATHML"><math> <mrow> <mi>d</mi> <mo>≥</mo> <mn>5</mn> </mrow> </math></EquationSource> </InlineEquation> over an algebraically closed field <i>k</i> of characteristic zero, it is shown in this paper that the bounded derived category <InlineEquation ID="IEq2"> <EquationSource Format="TEX">\({{\,\mathrm{D^b}\,}}(X^{[3]})\)</EquationSource> <EquationSource Format="MATHML"><math> <mrow> <mrow> <mspace width="0.166667em" /> <msup> <mi mathvariant="normal">D</mi> <mi mathvariant="normal">b</mi> </msup> <mspace width="0.166667em" /> </mrow> <mrow> <mo stretchy="false">(</mo> <msup> <mi>X</mi> <mrow> <mo stretchy="false">[</mo> <mn>3</mn> <mo stretchy="false">]</mo> </mrow> </msup> <mo stretchy="false">)</mo> </mrow> </mrow> </math></EquationSource> </InlineEquation> of the Hilbert scheme of three points admits a semi-orthogonal sequence of length <InlineEquation ID="IEq3"> <EquationSource Format="TEX">\(\left( {\begin{array}{c}d-3\\ 2\end{array}}\right) \)</EquationSource> <EquationSource Format="MATHML"><math> <mfenced close=")" open="("> <mrow> <mtable> <mtr> <mtd> <mrow> <mi>d</mi> <mo>-</mo> <mn>3</mn> </mrow> </mtd> </mtr> <mtr> <mtd> <mrow> <mrow /> <mn>2</mn> </mrow> </mtd> </mtr> </mtable> </mrow> </mfenced> </math></EquationSource> </InlineEquation>. Each subcategory in this sequence is equivalent to <InlineEquation ID="IEq4"> <EquationSource Format="TEX">\({{\,\mathrm{D^b}\,}}(X)\)</EquationSource> <EquationSource Format="MATHML"><math> <mrow> <mrow> <mspace width="0.166667em" /> <msup> <mi mathvariant="normal">D</mi> <mi mathvariant="normal">b</mi> </msup> <mspace width="0.166667em" /> </mrow> <mrow> <mo stretchy="false">(</mo> <mi>X</mi> <mo stretchy="false">)</mo> </mrow> </mrow> </math></EquationSource> </InlineEquation> and realized as the image of a Fourier–Mukai transform along a Grassmannian bundle <InlineEquation ID="IEq5"> <EquationSource Format="TEX">\(\mathbb {G} \rightarrow X\)</EquationSource> <EquationSource Format="MATHML"><math> <mrow> <mi mathvariant="double-struck">G</mi> <mo stretchy="false">→</mo> <mi>X</mi> </mrow> </math></EquationSource> </InlineEquation> parametrizing planar subschemes in <InlineEquation ID="IEq6"> <EquationSource Format="TEX">\(X^{[3]}\)</EquationSource> <EquationSource Format="MATHML"><math> <msup> <mi>X</mi> <mrow> <mo stretchy="false">[</mo> <mn>3</mn> <mo stretchy="false">]</mo> </mrow> </msup> </math></EquationSource> </InlineEquation>. The main ingredient in the proof is the computation of the normal bundle of <InlineEquation ID="IEq7"> <EquationSource Format="TEX">\(\mathbb {G}\)</EquationSource> <EquationSource Format="MATHML"><math> <mi mathvariant="double-struck">G</mi> </math></EquationSource> </InlineEquation> in <InlineEquation ID="IEq8"> <EquationSource Format="TEX">\(X^{[3]}\)</EquationSource> <EquationSource Format="MATHML"><math> <msup> <mi>X</mi> <mrow> <mo stretchy="false">[</mo> <mn>3</mn> <mo stretchy="false">]</mo> </mrow> </msup> </math></EquationSource> </InlineEquation>. An analogous result for generalized Kummer varieties is deduced at the end.</p>

错误:搜索内容不能为空,请输入英文关键词
错误:关键词超出字数限制,请精简
高级检索

A semi-orthogonal sequence in the derived category of the Hilbert scheme of three points

  • Erik Nikolov

摘要

For a smooth and quasi-projective variety X of dimension \(d \ge 5\) d 5 over an algebraically closed field k of characteristic zero, it is shown in this paper that the bounded derived category \({{\,\mathrm{D^b}\,}}(X^{[3]})\) D b ( X [ 3 ] ) of the Hilbert scheme of three points admits a semi-orthogonal sequence of length \(\left( {\begin{array}{c}d-3\\ 2\end{array}}\right) \) d - 3 2 . Each subcategory in this sequence is equivalent to \({{\,\mathrm{D^b}\,}}(X)\) D b ( X ) and realized as the image of a Fourier–Mukai transform along a Grassmannian bundle \(\mathbb {G} \rightarrow X\) G X parametrizing planar subschemes in \(X^{[3]}\) X [ 3 ] . The main ingredient in the proof is the computation of the normal bundle of \(\mathbb {G}\) G in \(X^{[3]}\) X [ 3 ] . An analogous result for generalized Kummer varieties is deduced at the end.