"Jack polynomials"의 두 판 사이의 차이

수학노트
둘러보기로 가기 검색하러 가기
imported>Pythagoras0
 
(사용자 2명의 중간 판 13개는 보이지 않습니다)
1번째 줄: 1번째 줄:
 
==introduction==
 
==introduction==
 
It has been known since the early 1970s \cite{Calogero69,Sutherland71,
 
It has been known since the early 1970s \cite{Calogero69,Sutherland71,
Sutherland72} that \eqref{Cp} with $\beta=2\gamma$ ---
+
Sutherland72} that \eqref{Cp} with <math>\beta=2\gamma</math> ---
to be denoted $\exp(-2\gamma W)$ in analogy with
+
to be denoted <math>\exp(-2\gamma W)</math> in analogy with
 
\eqref{Fza} --- is the absolute value squared of the ground-state  
 
\eqref{Fza} --- is the absolute value squared of the ground-state  
 
wave function for the Schr\"odinger operator \label{CSpage}
 
wave function for the Schr\"odinger operator \label{CSpage}
11번째 줄: 11번째 줄:
 
\]
 
\]
 
This operator, known as the Calogero--Sutherland Hamiltonian,
 
This operator, known as the Calogero--Sutherland Hamiltonian,
describes a system of $n$ identical quantum particles on the unit circle,
+
describes a system of <math>n</math> identical quantum particles on the unit circle,
with $\theta_i\in[0,2\pi)$ for $1\leq i\leq n$ the (angular)  
+
with <math>\theta_i\in[0,2\pi)</math> for <math>1\leq i\leq n</math> the (angular)  
 
positions of the particles. The interaction between the particles
 
positions of the particles. The interaction between the particles
is described by a $1/r^2$ two-body potential,
+
is described by a <math>1/r^2</math> two-body potential,
$2\abs{\sin((\theta_i - \theta_j)/2)}$
+
<math>2|\sin((\theta_i - \theta_j)/2)|</math>
 
being the cord-length between particles located at
 
being the cord-length between particles located at
$\theta_i$ and $\theta_j$.
+
<math>\theta_i</math> and <math>\theta_j</math>.
  
B.~Sutherland \cite{Sutherland71} showed that the eigenvalue $E_0$
+
B.~Sutherland \cite{Sutherland71} showed that the eigenvalue <math>E_0</math>
 
corresponding to the ground-state wave function
 
corresponding to the ground-state wave function
is given by $E_0=n(n^2-1)\gamma^2/12$. Subsequently he showed  
+
is given by <math>E_0=n(n^2-1)\gamma^2/12</math>. Subsequently he showed  
 
\cite{Sutherland72} that the conjugated operator
 
\cite{Sutherland72} that the conjugated operator
 
\begin{equation}\label{CO}
 
\begin{equation}\label{CO}
\eup^{\gamma W} (H - E_0) \eup^{-\gamma W} =
+
e^{\gamma W} (H - E_0) e^{-\gamma W} =
 
\sum_{i=1}^n \Bigl(x_i \frac{\partial}{\partial x_i} \Bigr)^2
 
\sum_{i=1}^n \Bigl(x_i \frac{\partial}{\partial x_i} \Bigr)^2
 
+ 2\gamma \sum_{\substack{i,j=1 \\ i\neq j}}^n
 
+ 2\gamma \sum_{\substack{i,j=1 \\ i\neq j}}^n
 
\frac{x_i + x_j}{x_i - x_j} \, \frac{\partial}{\partial x_i},
 
\frac{x_i + x_j}{x_i - x_j} \, \frac{\partial}{\partial x_i},
 
\end{equation}
 
\end{equation}
where $x_j := \exp(\iup \theta_j)$,
+
where <math>x_j := \exp(i \theta_j)</math>,
 
admits a complete set of symmetric polynomial eigenfunctions
 
admits a complete set of symmetric polynomial eigenfunctions
$P_{\la}^{(1/\gamma)}(x)$. These polynomials,
+
<math>P_{\lambda}^{(1/\gamma)}(x)</math>. These polynomials,
now referred to as Jack polynomials, depend on $x=(x_1,\dots,x_n)$
+
now referred to as Jack polynomials, depend on <math>x=(x_1,\dots,x_n)</math>
and are indexed by partitions $\la$ of at most $n$ parts;
+
and are indexed by partitions <math>\lambda</math> of at most <math>n</math> parts;
$\la=(\la_1,\dots,\la_n)$ with
+
<math>\lambda=(\lambda_1,\dots,\lambda_n)</math> with
$\la_1\geq \la_2\geq \dots\geq \la_n\geq 0$.  
+
<math>\lambda_1\geq \lambda_2\geq \dots\geq \lambda_n\geq 0</math>.  
With $m_{\la}$ denoting the monomial symmetric  
+
With <math>m_{\lambda}</math> denoting the monomial symmetric  
function indexed by $\la$ and $<$  
+
function indexed by <math>\lambda</math> and <math><</math>  
 
the dominance ordering on partitions, the  
 
the dominance ordering on partitions, the  
 
Jack polynomials have the structure
 
Jack polynomials have the structure
 
\begin{equation}\label{stu}
 
\begin{equation}\label{stu}
P_{\la}^{(1/\gamma)}(x) = m_{\la}(x) +  
+
P_{\lambda}^{(1/\gamma)}(x) = m_{\lambda}(x) +  
\sum_{\mu < \la} a_{\la\mu}\, m_{\mu}(x)
+
\sum_{\mu < \lambda} a_{\lambda\mu}\, m_{\mu}(x)
 
\end{equation}
 
\end{equation}
for some coefficients $a_{\la\mu}=a_{\la\mu}(\gamma)$.
+
for some coefficients <math>a_{\lambda\mu}=a_{\lambda\mu}(\gamma)</math>.
  
 
One fundamental property of the Jack polynomials is that they  
 
One fundamental property of the Jack polynomials is that they  
51번째 줄: 51번째 줄:
 
\langle f,g \rangle_{\gamma}:=\frac{1}{(2\pi)^n}
 
\langle f,g \rangle_{\gamma}:=\frac{1}{(2\pi)^n}
 
\int_{-\pi}^{\pi} \cdots \int_{-\pi}^{\pi}
 
\int_{-\pi}^{\pi} \cdots \int_{-\pi}^{\pi}
f(\eup^{\iup \theta}) g(\eup^{-\iup \theta})
+
f(e^{i \theta}) g(e^{-i \theta})
 
\prod_{1\le i<j\le n}
 
\prod_{1\le i<j\le n}
\abs{\eup^{\iup\theta_i}-\eup^{\iup\theta_j}}^{2\gamma} \,
+
|e^{i\theta_i}-e^{i\theta_j}|^{2\gamma} \,
\dup \theta_1 \cdots \dup \theta_n,
+
\,d \theta_1 \cdots \,d \theta_n,
 
\end{equation}
 
\end{equation}
where $f(\eup^{\iup \theta})=
+
where <math>f(e^{i \theta})=
f(\eup^{\iup \theta_1},\dots,\eup^{\iup \theta_n})$.
+
f(e^{i \theta_1},\dots,e^{i \theta_n})</math>.
 
To state the orthogonality as well as the quadratic norm evaluation let
 
To state the orthogonality as well as the quadratic norm evaluation let
 
\[
 
\[
\Poch{b}{\la}{\gamma}=\prod_{i\geq 1} (b+(1-i)\gamma)_{\la_i}
+
\Poch{b}{\lambda}{\gamma}=\prod_{i\geq 1} (b+(1-i)\gamma)_{\lambda_i}
 
\]
 
\]
with $(b)_n=b(b+1)\cdots(b+n-1)$ a Pochhammer symbol. Also let
+
with <math>(b)_n=b(b+1)\cdots(b+n-1)</math> a Pochhammer symbol. Also let
$c_{\la}(\gamma)$ and $c_{\la}'(\gamma)$ be given by
+
<math>c_{\lambda}(\gamma)</math> and <math>c_{\lambda}'(\gamma)</math> be given by
\begin{subequations}\label{ccp}
+
:<math>
 +
\label{ccp}
 
\begin{align}
 
\begin{align}
c_{\la}(\gamma)&=\prod_{s\in\la}(a(s)+l(s)\gamma+\gamma), \\
+
c_{\lambda}(\gamma)&=\prod_{s\in\lambda}(a(s)+l(s)\gamma+\gamma), \\
c'_{\la}(\gamma)&=\prod_{s\in\la}(a(s)+l(s)\gamma+1),
+
c'_{\lambda}(\gamma)&=\prod_{s\in\lambda}(a(s)+l(s)\gamma+1),
 
\end{align}
 
\end{align}
\end{subequations}
+
</math>
where $a(s)$ and $l(s)$ are the arm-length and leg-length of the  
+
where <math>a(s)</math> and <math>l(s)</math> are the arm-length and leg-length of the  
square $s$ in the diagram of the partition $\la$, and $\abs{\la}$
+
square <math>s</math> in the diagram of the partition <math>\lambda</math>, and <math>|\lambda|</math>
is the total number of boxes in the diagram of $\la$ \cite{Macdonald95}.
+
is the total number of boxes in the diagram of <math>\lambda</math> \cite{Macdonald95}.
 
Then
 
Then
 
\begin{equation}\label{OP}
 
\begin{equation}\label{OP}
\bigl\langle P_{\la}^{(1/\gamma)},P_{\mu}^{(1/\gamma)}\bigr\rangle_{\gamma}
+
\bigl\langle P_{\lambda}^{(1/\gamma)},P_{\mu}^{(1/\gamma)}\bigr\rangle_{\gamma}
=\delta_{\la\mu} \:
+
=\delta_{\lambda\mu} \:
\frac{c'_{\la}(\gamma)}
+
\frac{c'_{\lambda}(\gamma)}
{\Poch{1+(n-1)\gamma}{\la}{\gamma}}\:
+
{\Poch{1+(n-1)\gamma}{\lambda}{\gamma}}\:
 
\frac{\Gamma(1+n\gamma)}{\Gamma^n(1+\gamma)}\:
 
\frac{\Gamma(1+n\gamma)}{\Gamma^n(1+\gamma)}\:
P_{\la}^{(1/\gamma)}(1^n),
+
P_{\lambda}^{(1/\gamma)}(1^n),
 
\end{equation}
 
\end{equation}
where $\delta_{\la\mu}$ is the Kronecker delta function and
+
where <math>\delta_{\lambda\mu}</math> is the Kronecker delta function and
$(1^n)$ is shorthand for $(1,1,\dots,1)$.
+
<math>(1^n)</math> is shorthand for <math>(1,1,\dots,1)</math>.
 
The orthogonality relation is consistent with,  
 
The orthogonality relation is consistent with,  
 
but not an immediate consequence of the operator  
 
but not an immediate consequence of the operator  
90번째 줄: 91번째 줄:
 
This degeneracy can be removed by introducing the mutually commuting
 
This degeneracy can be removed by introducing the mutually commuting
 
Cherednik operators
 
Cherednik operators
$\xi_i$ for $1\leq i\leq n$ \cite{Cherednik91,Dunkl89}  
+
<math>\xi_i</math> for <math>1\leq i\leq n</math> \cite{Cherednik91,Dunkl89}  
 
\[
 
\[
 
\xi_i=1-i+\frac{x_i}{\gamma} \frac{\partial}{\partial x_i} +
 
\xi_i=1-i+\frac{x_i}{\gamma} \frac{\partial}{\partial x_i} +
96번째 줄: 97번째 줄:
 
\sum_{j=i+1}^n\frac{x_j}{x_i - x_j}\,(1 - s_{ij}),
 
\sum_{j=i+1}^n\frac{x_j}{x_i - x_j}\,(1 - s_{ij}),
 
\]
 
\]
where $s_{ij}$ acts by permutation  
+
where <math>s_{ij}</math> acts by permutation  
$x_i$ and $x_j$ and $1$ represents the identity operator.
+
<math>x_i</math> and <math>x_j</math> and <math>1</math> represents the identity operator.
Any symmetric combination of the $\xi_i$, and in particular
+
Any symmetric combination of the <math>\xi_i</math>, and in particular
$\prod_{i=1}^n (1-u\xi_i)$,
+
<math>\prod_{i=1}^n (1-u\xi_i)</math>,
 
has the Jack polynomials as simultaneous eigenfunctions.
 
has the Jack polynomials as simultaneous eigenfunctions.
  
109번째 줄: 110번째 줄:
 
\eqref{CNb2}, but also the more general quadratic norm evaluation  
 
\eqref{CNb2}, but also the more general quadratic norm evaluation  
 
of the Jack polynomials corresponding to \eqref{OP}  
 
of the Jack polynomials corresponding to \eqref{OP}  
with $\la=\mu$ \cite{Kakei98}.
+
with <math>\lambda=\mu</math> \cite{Kakei98}.
(For $\la=0$ this yields \eqref{CNb1}.)
+
(For <math>\lambda=0</math> this yields \eqref{CNb1}.)
With $\Delta(x)$ the Vandermonde product \eqref{VanderM} and $Y_{\pm}:=
+
With <math>\Delta(x)</math> the Vandermonde product \eqref{VanderM} and <math>Y_{\pm}:=
\gamma^{n(n-1)/2} \prod_{1\leq i<j\leq n}(\xi_i-\xi_j\mp 1)$,
+
\gamma^{n(n-1)/2} \prod_{1\leq i<j\leq n}(\xi_i-\xi_j\mp 1)</math>,
 
the Jack shift operators are defined by  
 
the Jack shift operators are defined by  
$G_{+}:=\Delta^{-1} Y_{+}$, $G_{-} = Y_{-}\Delta$.
+
<math>G_{+}:=\Delta^{-1} Y_{+}</math>, <math>G_{-} = Y_{-}\Delta</math>.
 
They have an adjoint type property with respect to the inner product  
 
They have an adjoint type property with respect to the inner product  
 
\eqref{InProd},
 
\eqref{InProd},
122번째 줄: 123번째 줄:
 
Also, with
 
Also, with
 
\begin{equation}\label{apm}
 
\begin{equation}\label{apm}
a_{\la}^{\pm}(\gamma)=\prod_{1\leq i<j\leq n}
+
a_{\lambda}^{\pm}(\gamma)=\prod_{1\leq i<j\leq n}
(\la_i-\la_j\pm 1+(j-i\mp 1)\gamma)
+
(\lambda_i-\lambda_j\pm 1+(j-i\mp 1)\gamma)
 
\end{equation}
 
\end{equation}
and $\delta$ the staircase partition $(n-1,n-2,\dots,1,0)$,  
+
and <math>\delta</math> the staircase partition <math>(n-1,n-2,\dots,1,0)</math>,  
 
the shift operators act on the Jack polynomials as
 
the shift operators act on the Jack polynomials as
\begin{subequations}\label{fr.2}
+
:<math>\label{fr.2}
 
\begin{align}
 
\begin{align}
G_{+} P_{\la+\delta}^{(1/\gamma)}&=a_{\la}^{+}(\gamma+1)  
+
G_{+} P_{\lambda+\delta}^{(1/\gamma)}&=a_{\lambda}^{+}(\gamma+1)  
P_{\la}^{(1/(\gamma+1))}, \\[2mm]
+
P_{\lambda}^{(1/(\gamma+1))}, \\[2mm]
G_{-} P_{\la}^{(1/(\gamma+1))}&=a_{\la}^{-}(\gamma+1)  
+
G_{-} P_{\lambda}^{(1/(\gamma+1))}&=a_{\lambda}^{-}(\gamma+1)  
P_{\la+\delta}^{(1/\gamma )}.
+
P_{\lambda+\delta}^{(1/\gamma )}.
 
\end{align}
 
\end{align}
\end{subequations}
+
</math>
 
It follows from \eqref{fr.1} and \eqref{fr.2} that  
 
It follows from \eqref{fr.1} and \eqref{fr.2} that  
 
\[
 
\[
\bigl\langle P_{\la}^{(1/(\gamma+1))},P_{\la}^{(1/(\gamma+1))}
+
\bigl\langle P_{\lambda}^{(1/(\gamma+1))},P_{\lambda}^{(1/(\gamma+1))}
 
\bigr\rangle_{\gamma+1}=
 
\bigr\rangle_{\gamma+1}=
\frac{a_{\la}^{-}(\gamma+1)}{a_{\la}^{+}(\gamma+1)}\:
+
\frac{a_{\lambda}^{-}(\gamma+1)}{a_{\lambda}^{+}(\gamma+1)}\:
\bigl\langle P_{\la+\delta}^{(1/\gamma)},P_{\la+\delta}^{(1/\gamma)}
+
\bigl\langle P_{\lambda+\delta}^{(1/\gamma)},P_{\lambda+\delta}^{(1/\gamma)}
 
\bigr\rangle_{\gamma}  
 
\bigr\rangle_{\gamma}  
 
\]
 
\]
 
and thus
 
and thus
 
\[
 
\[
\bigl\langle P_{\la}^{(1/(\gamma+k))},P_{\la}^{(1/(\gamma+k))}
+
\bigl\langle P_{\lambda}^{(1/(\gamma+k))},P_{\lambda}^{(1/(\gamma+k))}
 
\bigr\rangle_{\gamma+k}=
 
\bigr\rangle_{\gamma+k}=
\bigl\langle P_{\la+k\delta}^{(1/\gamma)},P_{\la+k\delta}^{(1/\gamma)}
+
\bigl\langle P_{\lambda+k\delta}^{(1/\gamma)},P_{\lambda+k\delta}^{(1/\gamma)}
 
\bigr\rangle_{\gamma}\:
 
\bigr\rangle_{\gamma}\:
 
\prod_{j=1}^{k-1}  
 
\prod_{j=1}^{k-1}  
\frac{a_{\la+j\delta}^{-}(\gamma+k-j)}{a_{\la+j\delta}^{+}(\gamma+k-j)}.
+
\frac{a_{\lambda+j\delta}^{-}(\gamma+k-j)}{a_{\lambda+j\delta}^{+}(\gamma+k-j)}.
 
\]
 
\]
Taking $\gamma=0$, using that $P_{\la}^{(\infty)}=m_{\la}$
+
Taking <math>\gamma=0</math>, using that <math>P_{\lambda}^{(\infty)}=m_{\lambda}</math>
 
(the monomial symmetric function) and   
 
(the monomial symmetric function) and   
 
\[
 
\[
159번째 줄: 160번째 줄:
 
m_{\mu}(1^n)
 
m_{\mu}(1^n)
 
\]
 
\]
which is $n!$ for $\mu=\la+k\delta$,
+
which is <math>n!</math> for <math>\mu=\lambda+k\delta</math>,
it follows that for nonnegative integer $k$
+
it follows that for nonnegative integer <math>k</math>
 
\label{pageJack2}
 
\label{pageJack2}
 
\begin{equation}\label{fr.3}
 
\begin{equation}\label{fr.3}
\bigl\langle P_{\la}^{(1/k)},P_{\la}^{(1/k)}\bigr\rangle_k
+
\bigl\langle P_{\lambda}^{(1/k)},P_{\lambda}^{(1/k)}\bigr\rangle_k
 
=n!\prod_{j=0}^{k-1} \frac{a_{\lambda+jk}^{-}(k-j)}
 
=n!\prod_{j=0}^{k-1} \frac{a_{\lambda+jk}^{-}(k-j)}
 
{a_{\lambda+jk}^{+}(k-j)}.
 
{a_{\lambda+jk}^{+}(k-j)}.
169번째 줄: 170번째 줄:
 
Using the evaluation formula \cite{Stanley89}  
 
Using the evaluation formula \cite{Stanley89}  
 
\begin{equation}\label{ef}
 
\begin{equation}\label{ef}
P_{\la}^{(1/\gamma)}(1^n)=\frac{[n\gamma]_{\la}^{(\gamma)}}
+
P_{\lambda}^{(1/\gamma)}(1^n)=\frac{[n\gamma]_{\lambda}^{(\gamma)}}
{c_{\la}(\gamma)}
+
{c_{\lambda}(\gamma)}
 
\end{equation}
 
\end{equation}
 
and the definitions \eqref{ccp} and \eqref{apm} it is now
 
and the definitions \eqref{ccp} and \eqref{apm} it is now
 
a straightforward exercise to verify that for  
 
a straightforward exercise to verify that for  
$\gamma=k$ \eqref{OP} coincides with \eqref{fr.3}.
+
<math>\gamma=k</math> \eqref{OP} coincides with \eqref{fr.3}.
 
Analytic continuation off the integers is then required to
 
Analytic continuation off the integers is then required to
 
establish
 
establish
\eqref{OP} for all $\Re(\gamma)>-1/n$.
+
\eqref{OP} for all <math>\Re(\gamma)>-1/n</math>.
  
 
\medskip
 
\medskip
184번째 줄: 185번째 줄:
 
R.P.~Stanley's Cauchy identity \cite{Stanley89}
 
R.P.~Stanley's Cauchy identity \cite{Stanley89}
 
\begin{equation}\label{CaP}
 
\begin{equation}\label{CaP}
\sum_{\la} \frac{c_{\la}(\gamma)}{c'_{\la}(\gamma)} \,
+
\sum_{\lambda} \frac{c_{\lambda}(\gamma)}{c'_{\lambda}(\gamma)} \,
P_{\la}^{(1/\gamma)}(x) P_{\la}^{(1/\gamma)}(y)=
+
P_{\lambda}^{(1/\gamma)}(x) P_{\lambda}^{(1/\gamma)}(y)=
 
\prod_{i=1}^n\prod_{j=1}^m (1-x_i y_j)^{-\gamma},
 
\prod_{i=1}^n\prod_{j=1}^m (1-x_i y_j)^{-\gamma},
 
\end{equation}
 
\end{equation}
where $x=(x_1,\dots,x_n)$, $y=(y_1,\dots,y_m)$. 
+
where <math>x=(x_1,\dots,x_n)</math>, <math>y=(y_1,\dots,y_m)</math>.
 
 
 
 
  
 
==related items==
 
==related items==
196번째 줄: 195번째 줄:
 
* [[Calogero–Moser-Sutherland model|Calogero–Sutherland model]]
 
* [[Calogero–Moser-Sutherland model|Calogero–Sutherland model]]
  
 
+
 
==memo==
 
==memo==
 
* http://icmt.illinois.edu/Workshops/WTPCM%20TALKS/bernevig.pdf
 
* http://icmt.illinois.edu/Workshops/WTPCM%20TALKS/bernevig.pdf
202번째 줄: 201번째 줄:
 
* http://citeseerx.ist.psu.edu/viewdoc/download?doi=10.1.1.160.7557&rep=rep1&type=pdf
 
* http://citeseerx.ist.psu.edu/viewdoc/download?doi=10.1.1.160.7557&rep=rep1&type=pdf
 
   
 
   
 
+
  
 
==encyclopedia==
 
==encyclopedia==
213번째 줄: 212번째 줄:
  
 
==articles==
 
==articles==
 +
* Charles F. Dunkl, Orthogonality Measure on the Torus for Vector-Valued Jack Polynomials, arXiv:1511.06721[math.RT], November 20 2015, http://arxiv.org/abs/1511.06721v3, 10.3842/SIGMA.2016.033, http://dx.doi.org/10.3842/SIGMA.2016.033, SIGMA 12 (2016), 033, 27 pages
 +
* Piotr Śniady, Top degree of Jack characters and enumeration of maps, http://arxiv.org/abs/1506.06361v2
 +
* Piotr Śniady, Structure coefficients for Jack characters: approximate factorization property, http://arxiv.org/abs/1603.04268v1
 +
* Dołęga, Maciej, and Valentin Féray. “Cumulants of Jack Symmetric Functions and <math>b</math>-Conjecture.” arXiv:1601.01501 [math], January 7, 2016. http://arxiv.org/abs/1601.01501.
 +
* Dunkl, Charles F. “Orthogonality Measure on the Torus for Vector-Valued Jack Polynomials.” arXiv:1511.06721 [math], November 20, 2015. http://arxiv.org/abs/1511.06721.
 +
* Śniady, Piotr 2015Top Degree of Jack Characters and Enumeration of Maps. arXiv:1506.06361 [math]. http://arxiv.org/abs/1506.06361, accessed July 11, 2015.
 +
* Lapointe, L., and P. Mathieu. ‘From Jack to Double Jack Polynomials via the Supersymmetric Bridge’. arXiv:1503.09029 [hep-Th, Physics:math-Ph], 31 March 2015. http://arxiv.org/abs/1503.09029.
 
* Ridout, David, and Simon Wood. “From Jack Polynomials to Minimal Model Spectra.” arXiv:1409.4847 [hep-Th], September 16, 2014. http://arxiv.org/abs/1409.4847.
 
* Ridout, David, and Simon Wood. “From Jack Polynomials to Minimal Model Spectra.” arXiv:1409.4847 [hep-Th], September 16, 2014. http://arxiv.org/abs/1409.4847.
 
* Dołęga, Maciej, and Valentin Féray. “On Kerov Polynomials for Jack Characters.” arXiv:1201.1806 [math], January 9, 2012. http://arxiv.org/abs/1201.1806.
 
* Dołęga, Maciej, and Valentin Féray. “On Kerov Polynomials for Jack Characters.” arXiv:1201.1806 [math], January 9, 2012. http://arxiv.org/abs/1201.1806.
221번째 줄: 227번째 줄:
 
[[분류:math and physics]]
 
[[분류:math and physics]]
 
[[분류:math]]
 
[[분류:math]]
 +
[[분류:symmetric polynomials]]
 +
[[분류:migrate]]
 +
 +
==메타데이터==
 +
===위키데이터===
 +
* ID :  [https://www.wikidata.org/wiki/Q6115970 Q6115970]
 +
===Spacy 패턴 목록===
 +
* [{'LOWER': 'jack'}, {'LEMMA': 'function'}]

2021년 2월 17일 (수) 02:57 기준 최신판

introduction

It has been known since the early 1970s \cite{Calogero69,Sutherland71, Sutherland72} that \eqref{Cp} with \(\beta=2\gamma\) --- to be denoted \(\exp(-2\gamma W)\) in analogy with \eqref{Fza} --- is the absolute value squared of the ground-state wave function for the Schr\"odinger operator \label{CSpage} \[ H = - \sum_{i=1}^n \frac{\partial^2}{\partial \theta_i^2} + \frac{1}{2}\gamma(\gamma-1)\sum_{1 \le i < j \le n} \frac{1}{\sin^2\bigl(\tfrac{1}{2}(\theta_i-\theta_j)\bigr)}. \] This operator, known as the Calogero--Sutherland Hamiltonian, describes a system of \(n\) identical quantum particles on the unit circle, with \(\theta_i\in[0,2\pi)\) for \(1\leq i\leq n\) the (angular) positions of the particles. The interaction between the particles is described by a \(1/r^2\) two-body potential, \(2|\sin((\theta_i - \theta_j)/2)|\) being the cord-length between particles located at \(\theta_i\) and \(\theta_j\).

B.~Sutherland \cite{Sutherland71} showed that the eigenvalue \(E_0\) corresponding to the ground-state wave function is given by \(E_0=n(n^2-1)\gamma^2/12\). Subsequently he showed \cite{Sutherland72} that the conjugated operator \begin{equation}\label{CO} e^{\gamma W} (H - E_0) e^{-\gamma W} = \sum_{i=1}^n \Bigl(x_i \frac{\partial}{\partial x_i} \Bigr)^2 + 2\gamma \sum_{\substack{i,j=1 \\ i\neq j}}^n \frac{x_i + x_j}{x_i - x_j} \, \frac{\partial}{\partial x_i}, \end{equation} where \(x_j := \exp(i \theta_j)\), admits a complete set of symmetric polynomial eigenfunctions \(P_{\lambda}^{(1/\gamma)}(x)\). These polynomials, now referred to as Jack polynomials, depend on \(x=(x_1,\dots,x_n)\) and are indexed by partitions \(\lambda\) of at most \(n\) parts; \(\lambda=(\lambda_1,\dots,\lambda_n)\) with \(\lambda_1\geq \lambda_2\geq \dots\geq \lambda_n\geq 0\). With \(m_{\lambda}\) denoting the monomial symmetric function indexed by \(\lambda\) and \(<\) the dominance ordering on partitions, the Jack polynomials have the structure \begin{equation}\label{stu} P_{\lambda}^{(1/\gamma)}(x) = m_{\lambda}(x) + \sum_{\mu < \lambda} a_{\lambda\mu}\, m_{\mu}(x) \end{equation} for some coefficients \(a_{\lambda\mu}=a_{\lambda\mu}(\gamma)\).

One fundamental property of the Jack polynomials is that they are orthogonal with respect to the inner product \label{pageJack1} \begin{equation}\label{InProd} \langle f,g \rangle_{\gamma}:=\frac{1}{(2\pi)^n} \int_{-\pi}^{\pi} \cdots \int_{-\pi}^{\pi} f(e^{i \theta}) g(e^{-i \theta}) \prod_{1\le i<j\le n} |e^{i\theta_i}-e^{i\theta_j}|^{2\gamma} \, \,d \theta_1 \cdots \,d \theta_n, \end{equation} where \(f(e^{i \theta})= f(e^{i \theta_1},\dots,e^{i \theta_n})\). To state the orthogonality as well as the quadratic norm evaluation let \[ \Poch{b}{\lambda}{\gamma}=\prod_{i\geq 1} (b+(1-i)\gamma)_{\lambda_i} \] with \((b)_n=b(b+1)\cdots(b+n-1)\) a Pochhammer symbol. Also let \(c_{\lambda}(\gamma)\) and \(c_{\lambda}'(\gamma)\) be given by \[ \label{ccp} \begin{align} c_{\lambda}(\gamma)&=\prod_{s\in\lambda}(a(s)+l(s)\gamma+\gamma), \\ c'_{\lambda}(\gamma)&=\prod_{s\in\lambda}(a(s)+l(s)\gamma+1), \end{align} \] where \(a(s)\) and \(l(s)\) are the arm-length and leg-length of the square \(s\) in the diagram of the partition \(\lambda\), and \(|\lambda|\) is the total number of boxes in the diagram of \(\lambda\) \cite{Macdonald95}. Then \begin{equation}\label{OP} \bigl\langle P_{\lambda}^{(1/\gamma)},P_{\mu}^{(1/\gamma)}\bigr\rangle_{\gamma} =\delta_{\lambda\mu} \: \frac{c'_{\lambda}(\gamma)} {\Poch{1+(n-1)\gamma}{\lambda}{\gamma}}\: \frac{\Gamma(1+n\gamma)}{\Gamma^n(1+\gamma)}\: P_{\lambda}^{(1/\gamma)}(1^n), \end{equation} where \(\delta_{\lambda\mu}\) is the Kronecker delta function and \((1^n)\) is shorthand for \((1,1,\dots,1)\). The orthogonality relation is consistent with, but not an immediate consequence of the operator \eqref{CO} being self-adjoint with respect to \eqref{InProd}. The complication is that not all eigenvalues of \eqref{CO} are distinct. This degeneracy can be removed by introducing the mutually commuting Cherednik operators \(\xi_i\) for \(1\leq i\leq n\) \cite{Cherednik91,Dunkl89} \[ \xi_i=1-i+\frac{x_i}{\gamma} \frac{\partial}{\partial x_i} + \sum_{j=1}^{i-1}\frac{x_i}{x_i - x_j}\,(1 - s_{ij}) + \sum_{j=i+1}^n\frac{x_j}{x_i - x_j}\,(1 - s_{ij}), \] where \(s_{ij}\) acts by permutation \(x_i\) and \(x_j\) and \(1\) represents the identity operator. Any symmetric combination of the \(\xi_i\), and in particular \(\prod_{i=1}^n (1-u\xi_i)\), has the Jack polynomials as simultaneous eigenfunctions.

The Cherednik operators can be used to construct the Jack polynomial shift operator --- a special case of the shift operators studied by Heckman and Opdam, and used by the latter to prove the Macdonald integral and constant term conjectures. Properties of the Jack shift operator not only imply \eqref{CNb1} or, equivalently, \eqref{CNb2}, but also the more general quadratic norm evaluation of the Jack polynomials corresponding to \eqref{OP} with \(\lambda=\mu\) \cite{Kakei98}. (For \(\lambda=0\) this yields \eqref{CNb1}.) With \(\Delta(x)\) the Vandermonde product \eqref{VanderM} and \(Y_{\pm}:= \gamma^{n(n-1)/2} \prod_{1\leq i<j\leq n}(\xi_i-\xi_j\mp 1)\), the Jack shift operators are defined by \(G_{+}:=\Delta^{-1} Y_{+}\), \(G_{-} = Y_{-}\Delta\). They have an adjoint type property with respect to the inner product \eqref{InProd}, \begin{equation}\label{fr.1} \langle G_{+}f,g\rangle_{\gamma+1}=\langle f,G_{-} g\rangle_{\gamma}. \end{equation} Also, with \begin{equation}\label{apm} a_{\lambda}^{\pm}(\gamma)=\prod_{1\leq i<j\leq n} (\lambda_i-\lambda_j\pm 1+(j-i\mp 1)\gamma) \end{equation} and \(\delta\) the staircase partition \((n-1,n-2,\dots,1,0)\), the shift operators act on the Jack polynomials as \[\label{fr.2} \begin{align} G_{+} P_{\lambda+\delta}^{(1/\gamma)}&=a_{\lambda}^{+}(\gamma+1) P_{\lambda}^{(1/(\gamma+1))}, \\[2mm] G_{-} P_{\lambda}^{(1/(\gamma+1))}&=a_{\lambda}^{-}(\gamma+1) P_{\lambda+\delta}^{(1/\gamma )}. \end{align} \] It follows from \eqref{fr.1} and \eqref{fr.2} that \[ \bigl\langle P_{\lambda}^{(1/(\gamma+1))},P_{\lambda}^{(1/(\gamma+1))} \bigr\rangle_{\gamma+1}= \frac{a_{\lambda}^{-}(\gamma+1)}{a_{\lambda}^{+}(\gamma+1)}\: \bigl\langle P_{\lambda+\delta}^{(1/\gamma)},P_{\lambda+\delta}^{(1/\gamma)} \bigr\rangle_{\gamma} \] and thus \[ \bigl\langle P_{\lambda}^{(1/(\gamma+k))},P_{\lambda}^{(1/(\gamma+k))} \bigr\rangle_{\gamma+k}= \bigl\langle P_{\lambda+k\delta}^{(1/\gamma)},P_{\lambda+k\delta}^{(1/\gamma)} \bigr\rangle_{\gamma}\: \prod_{j=1}^{k-1} \frac{a_{\lambda+j\delta}^{-}(\gamma+k-j)}{a_{\lambda+j\delta}^{+}(\gamma+k-j)}. \] Taking \(\gamma=0\), using that \(P_{\lambda}^{(\infty)}=m_{\lambda}\) (the monomial symmetric function) and \[ \bigl\langle m_{\mu},m_{\mu} \bigr\rangle_0= \text{CT}\Bigl( m_{\mu}(x)m_{\mu}(x^{-1})\Bigr)= m_{\mu}(1^n) \] which is \(n!\) for \(\mu=\lambda+k\delta\), it follows that for nonnegative integer \(k\) \label{pageJack2} \begin{equation}\label{fr.3} \bigl\langle P_{\lambda}^{(1/k)},P_{\lambda}^{(1/k)}\bigr\rangle_k =n!\prod_{j=0}^{k-1} \frac{a_{\lambda+jk}^{-}(k-j)} {a_{\lambda+jk}^{+}(k-j)}. \end{equation} Using the evaluation formula \cite{Stanley89} \begin{equation}\label{ef} P_{\lambda}^{(1/\gamma)}(1^n)=\frac{[n\gamma]_{\lambda}^{(\gamma)}} {c_{\lambda}(\gamma)} \end{equation} and the definitions \eqref{ccp} and \eqref{apm} it is now a straightforward exercise to verify that for \(\gamma=k\) \eqref{OP} coincides with \eqref{fr.3}. Analytic continuation off the integers is then required to establish \eqref{OP} for all \(\Re(\gamma)>-1/n\).

\medskip

A further fundamental property of the Jack polynomials is R.P.~Stanley's Cauchy identity \cite{Stanley89} \begin{equation}\label{CaP} \sum_{\lambda} \frac{c_{\lambda}(\gamma)}{c'_{\lambda}(\gamma)} \, P_{\lambda}^{(1/\gamma)}(x) P_{\lambda}^{(1/\gamma)}(y)= \prod_{i=1}^n\prod_{j=1}^m (1-x_i y_j)^{-\gamma}, \end{equation} where \(x=(x_1,\dots,x_n)\), \(y=(y_1,\dots,y_m)\).

related items


memo


encyclopedia


articles

  • Charles F. Dunkl, Orthogonality Measure on the Torus for Vector-Valued Jack Polynomials, arXiv:1511.06721[math.RT], November 20 2015, http://arxiv.org/abs/1511.06721v3, 10.3842/SIGMA.2016.033, http://dx.doi.org/10.3842/SIGMA.2016.033, SIGMA 12 (2016), 033, 27 pages
  • Piotr Śniady, Top degree of Jack characters and enumeration of maps, http://arxiv.org/abs/1506.06361v2
  • Piotr Śniady, Structure coefficients for Jack characters: approximate factorization property, http://arxiv.org/abs/1603.04268v1
  • Dołęga, Maciej, and Valentin Féray. “Cumulants of Jack Symmetric Functions and \(b\)-Conjecture.” arXiv:1601.01501 [math], January 7, 2016. http://arxiv.org/abs/1601.01501.
  • Dunkl, Charles F. “Orthogonality Measure on the Torus for Vector-Valued Jack Polynomials.” arXiv:1511.06721 [math], November 20, 2015. http://arxiv.org/abs/1511.06721.
  • Śniady, Piotr 2015Top Degree of Jack Characters and Enumeration of Maps. arXiv:1506.06361 [math]. http://arxiv.org/abs/1506.06361, accessed July 11, 2015.
  • Lapointe, L., and P. Mathieu. ‘From Jack to Double Jack Polynomials via the Supersymmetric Bridge’. arXiv:1503.09029 [hep-Th, Physics:math-Ph], 31 March 2015. http://arxiv.org/abs/1503.09029.
  • Ridout, David, and Simon Wood. “From Jack Polynomials to Minimal Model Spectra.” arXiv:1409.4847 [hep-Th], September 16, 2014. http://arxiv.org/abs/1409.4847.
  • Dołęga, Maciej, and Valentin Féray. “On Kerov Polynomials for Jack Characters.” arXiv:1201.1806 [math], January 9, 2012. http://arxiv.org/abs/1201.1806.
  • Sahi, Siddhartha. “A New Scalar Product for Nonsymmetric Jack Polynomials.” International Mathematics Research Notices 1996, no. 20 (January 1, 1996): 997–1004. doi:10.1155/S107379289600061X.

메타데이터

위키데이터

Spacy 패턴 목록

  • [{'LOWER': 'jack'}, {'LEMMA': 'function'}]