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FJ-LMI Seminar
Seminar information archive ～05/23｜Next seminar｜Future seminars 05/24～
| Organizer(s) | Toshiyuki Kobayashi, Michael Pevzner |
|---|
2024/11/27
13:30-14:30 Room #122 (Graduate School of Math. Sci. Bldg.)
Hidenori FUJIWARA (OCAMI, Kindai University)
Inductions and restrictions of unitary representations for exponential solvable Lie groups. (英語)
https://fj-lmi.cnrs.fr/seminars/
Hidenori FUJIWARA (OCAMI, Kindai University)
Inductions and restrictions of unitary representations for exponential solvable Lie groups. (英語)
[ Abstract ]
Let $G = \exp \mathfrak g$ be a connected and simply connected real nilpotent Lie group with Lie algebra $\mathfrak g$, $H = \exp \mathfrak h$ an analytic subgroup of $G$ with Lie algebra $\mathfrak h$, $\chi$ a unitary character of $H$ and $\tau = \text{ind}_H^G \chi$ the monomial representation of $G$ induced from $\chi$. Let $D_{\tau}(G/H)$ be the algebra of the $G$-invariant differential operators on the line bundle over $G/H$ associated to the data $(H,\chi)$. We denote by $C_{\tau}$ the center of $D_{\tau}(G/H)$. We know that $\chi$ is written as ${\chi}_f$, where $\chi_f(\exp X) = e^{if(X)} (X \in \mathfrak h)$ with a certain $f \in {\mathfrak g}^*$ verifying $f([\mathfrak h,\mathfrak h]) = \{0\}$. Let $S(\mathfrak g)$ be the symmetric algebra of $\mathfrak g$ and ${\mathfrak a}_{\tau} = \{X + \sqrt{-1}f(X) ; X \in \mathfrak h\}.$ We regard $S(\mathfrak g)$ as the algebra of polynomial functions on ${\mathfrak g}^*$ by $X(\ell) = \sqrt{-1}\ell(X)$ for $X \in \mathfrak g, \ell \in {\mathfrak g}^*$. Now, $S(\mathfrak g)$ possesses the Poisson structure $\{,\}$ well determined by the equality $\{X,Y\} = [X,Y]$ if $X, Y$ are in $\mathfrak g$. Let us consider the algebra $(S(\mathfrak g)/S(\mathfrak g)\overline{{\mathfrak a}_{\tau}})^H$ of the $H$-invariant polynomial functions on the affine subspace ${\Gamma}_{\tau} = \{\ell \in {\mathfrak g}^* : \ell(X) = f(X), X \in \mathfrak h\}$ of ${\mathfrak g}^*$. This inherits the Poisson structure from $S(\mathfrak g)$. We denote by $Z_{\tau}$ its Poisson center. Michel Duflo asked: the two algebras $C_{\tau}$ and $Z_{\tau}$, are they isomorphic? Here we provide a positive answer to this question.
[ Reference URL ]Let $G = \exp \mathfrak g$ be a connected and simply connected real nilpotent Lie group with Lie algebra $\mathfrak g$, $H = \exp \mathfrak h$ an analytic subgroup of $G$ with Lie algebra $\mathfrak h$, $\chi$ a unitary character of $H$ and $\tau = \text{ind}_H^G \chi$ the monomial representation of $G$ induced from $\chi$. Let $D_{\tau}(G/H)$ be the algebra of the $G$-invariant differential operators on the line bundle over $G/H$ associated to the data $(H,\chi)$. We denote by $C_{\tau}$ the center of $D_{\tau}(G/H)$. We know that $\chi$ is written as ${\chi}_f$, where $\chi_f(\exp X) = e^{if(X)} (X \in \mathfrak h)$ with a certain $f \in {\mathfrak g}^*$ verifying $f([\mathfrak h,\mathfrak h]) = \{0\}$. Let $S(\mathfrak g)$ be the symmetric algebra of $\mathfrak g$ and ${\mathfrak a}_{\tau} = \{X + \sqrt{-1}f(X) ; X \in \mathfrak h\}.$ We regard $S(\mathfrak g)$ as the algebra of polynomial functions on ${\mathfrak g}^*$ by $X(\ell) = \sqrt{-1}\ell(X)$ for $X \in \mathfrak g, \ell \in {\mathfrak g}^*$. Now, $S(\mathfrak g)$ possesses the Poisson structure $\{,\}$ well determined by the equality $\{X,Y\} = [X,Y]$ if $X, Y$ are in $\mathfrak g$. Let us consider the algebra $(S(\mathfrak g)/S(\mathfrak g)\overline{{\mathfrak a}_{\tau}})^H$ of the $H$-invariant polynomial functions on the affine subspace ${\Gamma}_{\tau} = \{\ell \in {\mathfrak g}^* : \ell(X) = f(X), X \in \mathfrak h\}$ of ${\mathfrak g}^*$. This inherits the Poisson structure from $S(\mathfrak g)$. We denote by $Z_{\tau}$ its Poisson center. Michel Duflo asked: the two algebras $C_{\tau}$ and $Z_{\tau}$, are they isomorphic? Here we provide a positive answer to this question.
https://fj-lmi.cnrs.fr/seminars/
