text/deligne.tex
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     6 about the action of the little disks operad on Hochschild cochains.
     6 about the action of the little disks operad on Hochschild cochains.
     7 The first several paragraphs lead up to a precise statement of the result
     7 The first several paragraphs lead up to a precise statement of the result
     8 (Theorem \ref{thm:deligne} below).
     8 (Theorem \ref{thm:deligne} below).
     9 Then we give the proof.
     9 Then we give the proof.
    10 
    10 
    11 \nn{Does this generalization encompass Kontsevich's proposed generalization from \cite[\S2.5]{MR1718044}, 
    11 %\nn{Does this generalization encompass Kontsevich's proposed generalization from \cite[\S2.5]{MR1718044}, 
    12 that (I think...) the Hochschild homology of an $E_n$ algebra is an $E_{n+1}$ algebra? -S}
    12 %that (I think...) the Hochschild homology of an $E_n$ algebra is an $E_{n+1}$ algebra? -S}
    13 
    13 
    14 %from http://www.ams.org/mathscinet-getitem?mr=1805894
    14 %from http://www.ams.org/mathscinet-getitem?mr=1805894
    15 %Different versions of the geometric counterpart of Deligne's conjecture have been proven by Tamarkin [``Formality of chain operad of small squares'', preprint, http://arXiv.org/abs/math.QA/9809164], the reviewer [in Confˇrence Moshˇ Flato 1999, Vol. II (Dijon), 307--331, Kluwer Acad. Publ., Dordrecht, 2000; MR1805923 (2002d:55009)], and J. E. McClure and J. H. Smith [``A solution of Deligne's conjecture'', preprint, http://arXiv.org/abs/math.QA/9910126] (see also a later simplified version [J. E. McClure and J. H. Smith, ``Multivariable cochain operations and little $n$-cubes'', preprint, http://arXiv.org/abs/math.QA/0106024]). The paper under review gives another proof of Deligne's conjecture, which, as the authors indicate, may be generalized to a proof of a higher-dimensional generalization of Deligne's conjecture, suggested in [M. Kontsevich, Lett. Math. Phys. 48 (1999), no. 1, 35--72; MR1718044 (2000j:53119)]. 
    15 %Different versions of the geometric counterpart of Deligne's conjecture have been proven by Tamarkin [``Formality of chain operad of small squares'', preprint, http://arXiv.org/abs/math.QA/9809164], the reviewer [in Confˇrence Moshˇ Flato 1999, Vol. II (Dijon), 307--331, Kluwer Acad. Publ., Dordrecht, 2000; MR1805923 (2002d:55009)], and J. E. McClure and J. H. Smith [``A solution of Deligne's conjecture'', preprint, http://arXiv.org/abs/math.QA/9910126] (see also a later simplified version [J. E. McClure and J. H. Smith, ``Multivariable cochain operations and little $n$-cubes'', preprint, http://arXiv.org/abs/math.QA/0106024]). The paper under review gives another proof of Deligne's conjecture, which, as the authors indicate, may be generalized to a proof of a higher-dimensional generalization of Deligne's conjecture, suggested in [M. Kontsevich, Lett. Math. Phys. 48 (1999), no. 1, 35--72; MR1718044 (2000j:53119)]. 
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   190 				 \stackrel{\id\ot\alpha_1}{\to} \bc_*(R_1\cup N_1)
   190 				 \stackrel{\id\ot\alpha_1}{\to} \bc_*(R_1\cup N_1)
   191 				 \stackrel{f_1}{\to} \bc_*(R_2\cup M_2) \stackrel{\id\ot\alpha_2}{\to}
   191 				 \stackrel{f_1}{\to} \bc_*(R_2\cup M_2) \stackrel{\id\ot\alpha_2}{\to}
   192 				 \cdots  \stackrel{\id\ot\alpha_k}{\to} \bc_*(R_k\cup N_k)
   192 				 \cdots  \stackrel{\id\ot\alpha_k}{\to} \bc_*(R_k\cup N_k)
   193 				 \stackrel{f_k}{\to} \bc_*(N_0)
   193 				 \stackrel{f_k}{\to} \bc_*(N_0)
   194 \]
   194 \]
   195 (Recall that the maps $\id\ot\alpha_i$ were defined in \S\ref{ss:module-morphisms}s.)
   195 (Recall that the maps $\id\ot\alpha_i$ were defined in \S\ref{ss:module-morphisms}.)
   196 \nn{need to double check case where $\alpha_i$'s are not closed.}
       
   197 It is easy to check that the above definition is compatible with the equivalence relations
   196 It is easy to check that the above definition is compatible with the equivalence relations
   198 and also the operad structure.
   197 and also the operad structure.
   199 We can reinterpret the above as a chain map
   198 We can reinterpret the above as a chain map
   200 \[
   199 \[
   201 	p: C_0(FG^n_{\ol{M}\ol{N}})\ot \hom(\bc_*(M_1), \bc_*(N_1))\ot\cdots\ot\hom(\bc_*(M_k), \bc_*(N_k))
   200 	p: C_0(FG^n_{\ol{M}\ol{N}})\ot \hom(\bc_*(M_1), \bc_*(N_1))\ot\cdots\ot\hom(\bc_*(M_k), \bc_*(N_k))