"Y-system and functional dilogarithm identities"의 두 판 사이의 차이

수학노트
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==introduction==
 
==introduction==
 +
* {{수학노트|url=함수_다이로그_항등식(functional_dilogarithm_identity)}}
 +
* <math>\mathbb{Y}(X,X')</math> the order of <math>X</math> and <math>X'</math> matters!
 +
* Caracciolo, R., F. Gliozzi, and R. Tateo in 1999 proves the functional dilogarithm identities associated ADExADE Y-systems assuming the periodicity of restricted T-system
  
* [http://pythagoras0.springnote.com/pages/4682477 체비셰프 다항식]<br><math>U_n(x)^2=1+U_{n-1}(x)U_{n+1}(x)</math><br>
 
* [http://pythagoras0.springnote.com/pages/6904713 정다각형의 대각선의 길이]<br><math>r_i^2=1+r_{i-1}r_{i+1}, 1\leq i \leq n-3</math><br>
 
* Question : for what values of <math>r_1=x</math>, is the recurrence <math>r_i^2=1+r_{i-1}r_{i+1}</math> periodic? (<math>r_0=1</math>)
 
  
 
 
  
# A := RecurrenceTable[{a[n] a[n - 2] + 1 == a[n - 1]^2, a[1] == x,<br>    a[2] == y}, a, {n, 10}]<br> Simplify[A]
+
==main results==
 +
===level restricted Y-system===
 +
* Suppose that a family of positive real numbers
 +
:<math>\{Y^{(a)}_m(u)\mid a\in I, 1\leq m \leq t_a\ell-1,
 +
u\in \mathbb{Z}\}</math>
 +
satisfy the level <math>\ell</math> restricted Y-system for <math>\mathfrak{g}</math>.
 +
Then, the following identities hold:
 +
\begin{align}\label{t:eq:DI2}
 +
\frac{6}{\pi^2}\sum_{a\in I}\sum_{m=1}^{t_a\ell-1}
 +
\sum_{u=0}^{2(h^{\vee}+\ell)-1}
 +
L\left(
 +
\frac{Y^{(a)}_m(u)}{1+Y^{(a)}_m(u)}
 +
\right)
 +
&=
 +
2t(\ell h - h^{\vee})\mathrm{rank}\,\mathfrak{g},
 +
\end{align}
 +
where <math>h</math> is the Coxeter number of <math>{\mathfrak g}</math>.
 +
* in simply-laced case, we get
 +
:<math>
 +
\begin{align}
 +
\frac{6}{\pi^2}\sum_{a\in I}\sum_{m=1}^{\ell-1}
 +
\sum_{u=0}^{2(h+\ell)-1}
 +
L\left(
 +
\frac{Y^{(a)}_m(u)}{1+Y^{(a)}_m(u)}
 +
\right)
 +
&=
 +
2(\ell h - h)r=2h(\ell-1)r
 +
\end{align}
 +
</math>
  
* Laurent phenomenon is true
+
===Y-systems for a pair of Dynkin diagrams===
* total positivity is broken
+
* Bloch group element
* 정오각형의 경우
+
:<math>
* <math>r_i^2=1+r_{i-1}r_{i+1}</math>, <math>r_0=1,r_3=1</math>
+
\sum_{(\mathbf{i},u)\in S_{+}} Y_{\mathbf{i}}(u)\wedge (1+Y_{\mathbf{i}}(u))=0\in \Lambda^2 \mathbb{Q}(y)^{\times}
* 3가지 점화식의 해가 존재
+
</math> where <math>S_{+}=\{(\mathbf{i},u) |0\leq u \leq 2(h+h')-1,(\mathbf{i},u)\in P_{+}\}</math>.
* <math>\{1,-1,0,1\}</math><math>\{1,\frac{-\sqrt{5}+1}{2},\frac{-\sqrt{5}+1}{2},1 \}</math> , <math>\{1,\frac{\sqrt{5}+1}{2},\frac{\sqrt{5}+1}{2},1 \}</math>
+
* functional dilogarithm identity
 +
:<math>
 +
\sum_{(\mathbf{i},u)\in S_{+}}L\left(\frac{Y_\mathbf{i}(u)}{1+Y_\mathbf{i}(u)}\right)=h r r' L(1)
 +
</math>
  
 
 
  
# A := RecurrenceTable[{a[n] a[n - 2] + 1 == a[n - 1]^2, a[1] == 1,<br>    a[2] == 2 y}, a, {n, 10}]<br> Simplify[A]<br> NSolve[-4 y + 8 y^3 == 1, y]<br> {1, 2 y, -1 + 4 y^2, -4 y + 8 y^3,<br>    1 - 12 y^2 +<br>     16 y^4} /. {{y -> -0.5`}, {y -> -0.30901699437494745`}, {y -><br>      0.8090169943749475`}} // TableForm
+
==bicoloring==
 +
* what's <math>P_{+}</math>?
 +
* We give an alternate bicoloring on the pair of Dynkin diagrams. Let us fix bipartite decompositions of <math>I</math> and <math>I'</math>.
 +
* Let <math> \mathbf{I}= I\times I'</math> and <math>\mathbf{I}=\mathbf{I}_{+}\sqcup \mathbf{I}_{-}</math> where <math>\mathbf{I}_{+}=(I_{+}\times I'_{+}) \sqcup (I_{-}\times I'_{-})</math> and <math>\mathbf{I}_{-}=(I_{+}\times I'_{-}) \sqcup (I_{-}\times I'_{+})</math>.
 +
* Let <math>\epsilon : \mathbf{I}\to \{1,-1\}</math> be the function defined by <math>\epsilon(\mathbf{i})=\pm 1</math> for <math>\mathbf{i}\in \mathbf{I}_{\pm}</math> and <math>P_{\pm} =\{(\mathbf{i},u)\in \mathbf{I}\times\mathbb{Z}| \epsilon(\mathbf{i})(-1)^u=\pm 1\}</math>.  
 +
* Roughly speaking, we want our alternate bicoloring interchanges their colors as <math>u\in \mathbb{Z}</math> changes by 1.  
  
 
 
  
 
+
==an example==
 
+
* compute <math>\mathbb{Y}(A_2,A_1)</math> explicitly
 
+
* <math>y_{m-1}y_{m+1}=y_m+1</math>
 
+
* Start with two variables <math>y_1,y_2</math>.
==total positivity==
+
* <math>y_3y_1=y_2+1</math>. so <math>y_3=\frac{y_2+1}{y_1}</math>
 
+
* <math>y_2y_4=y_3+1 </math>implies <math>y_4=\frac{y_3+1}{y_2}=\frac{y_1+y_2+1}{y_1y_2}</math>
* <math>r_{i-1}r_{i+1}=r_i^2+1</math>
+
* <math>y_3y_5=y_4+1</math> implies <math>y_5=\frac{y_4+1}{y_3}= \frac{y_1+1}{y_2}</math> we are getting Laurent polynomials
 
+
* <math>y_4y_6=y_5</math> implies <math>y_6=\frac{y_5+1}{y_4}= \frac{\frac{y_1+1}{y_2}+1}{\frac{y_1+y_2+1}{y_1y_2}}=\frac{y_1(y_1+1)+y_1y_2}{y_1+y_2+1}=y_1</math>
# A := RecurrenceTable[{a[n] a[n - 2] - 1 == a[n - 1]^2, a[1] == x,<br>    a[2] == y}, a, {n, 10}]<br> Simplify[A]
+
* [[rank 2 cluster algebra]]
 
 
* [[rank 2 cluster algebra examples]]
 
 
 
 
 
  
 
 
  
==relation to 5-term relation==
+
===observations===
 +
* we saw that :<math>S=\left\{x,y,\frac{y+1}{x},\frac{x+y+1}{x y},\frac{x+1}{y}\right\}</math> forms a half-period of <math>\mathbb{Y}(A_2,A_1)</math>.
 +
* So we have <math>r=2,h=3</math> and <math>r'=1,h'=2</math>.
 +
* They are all Laurent polynomials in <math>x</math> and <math>y</math>.
  
* [http://pythagoras0.springnote.com/pages/5956565 5항 관계식 (5-term relation)]<br><math>1-x_{i}=x_{i-1}x_{i+1}</math><br>
 
  
 
+
===dilogarithm identities===
 
+
* From this, one can get functional dilogarithm identities
 
+
\begin{align}
 
+
&\sum_{a\in S}L\left(\frac{a}{1+a}\right) \notag \\
==five-term relation of dilogarithm==
+
=&
 +
L\left(\frac{x}{1+x}\right)+L\left(\frac{y}{1+y}\right)+L\left(\frac{1+y}{x (1+\frac{1+y}{x})}\right)+L\left(\frac{1+x+y}{x y (1+\frac{1+x+y}{x y})}\right)+L\left(\frac{1+x}{(1+\frac{1+x}{y}) y}\right) \notag
 +
\\
 +
=& L\left(\frac{x}{x+1}\right)+L\left(\frac{y}{y+1}\right)+L\left(\frac{y+1}{x+y+1}\right)+L\left(\frac{x+y+1}{x y+x+y+1}\right)+L\left(\frac{x+1}{x+y+1}\right) \notag \\
 +
=&3L(1)=\frac{\pi^2}{2} \notag
 +
\end{align}
 +
and
 +
\begin{align}
 +
&\sum_{a\in S}L\left(\frac{1}{1+a}\right) \notag \\
 +
=&
 +
L\left(\frac{1}{x+1}\right)+L\left(\frac{1}{y+1}\right)+L\left(\frac{1}{\frac{y+1}{x}+1}\right)+L\left(\frac{1}{\frac{x+y+1}{x y}+1}\right)+L\left(\frac{1}{\frac{x+1}{y}+1}\right) \notag \\
 +
=& L\left(\frac{1}{x+1}\right)+L\left(\frac{1}{y+1}\right)+L\left(\frac{x}{x+y+1}\right)+L\left(\frac{x y}{x y+x+y+1}\right)+L\left(\frac{y}{x+y+1}\right) \notag \\
 +
=&2L(1)=\frac{\pi^2}{3} \notag.
 +
\end{align}
 
* {{수학노트|url=5항_관계식_(5-term_relation)}}
 
* {{수학노트|url=5항_관계식_(5-term_relation)}}
* [http://pythagoras0.springnote.com/pages/5956565 5항 관계식 (5-term relation)]<br>
+
* [[Dilogarithm identity for CFT revisited]]
*  로저스 다이로그 함수 <math>L(x)</math>에 대하여 다음이 성립한다<br><math>0\leq x,y\leq 1</math> 일 때,  :<math>L(x)+L(1-xy)+L(y)+L\left(\frac{1-y}{1-xy}\right)+L\left(\frac{1-x}{1-xy}\right)=\frac{\pi^2}{2}</math><br>
 
* <math>1-x_{i}=x_{i-1}x_{i+1}</math> 를 만족시키는 다섯개의 수<br>
 
* is this also an example of a cluster variable?
 
* [[asymptotic analysis of basic hypergeometric series]]
 
 
 
 
 
 
 
# f[{x_, y_, z_, w_}] := Simplify[(x - z)/(x - w)*(y - w)/(y - z)]<br> A := Permutations[{0, 1, w, z}]<br> Table[Limit[f[A[[i]]], w -> \[Infinity]], {i, 24}]<br> B := Subsets[{0, x*y, 1, y, z}, {4}]<br> g[i_] := Table[<br>   Limit[f[n], z -> \[Infinity]], {n, Permutations[B[[i]]]}]<br> Table[f[B[[i]]], {i, 1, 5}]<br> Table[g[i], {i, 5}]
 
  
 
 
 
 
==rank 2 example==
 
 
* [[rank 2 cluster algebra]]
 
 
<math>y_{m-1}y_{m+1}=y_m+1</math>
 
 
Start with two variables <math>y_1,y_2</math>.
 
 
<math>y_3y_1=y_2+1</math>. so <math>y_3=\frac{y_2+1}{y_1}</math>
 
 
<math>y_2y_4=y_3+1 </math>implies <math>y_4=\frac{y_3+1}{y_2}=\frac{y_1+y_2+1}{y_1y_2}</math>
 
 
<math>y_3y_5=y_4+1</math> implies <math>y_5=\frac{y_4+1}{y_3}= \frac{y_1+1}{y_2}</math> we are getting Laurent polynomials
 
 
<math>y_4y_6=y_5</math> implies <math>y_6=\frac{y_5+1}{y_4}= \frac{\frac{y_1+1}{y_2}+1}{\frac{y_1+y_2+1}{y_1y_2}}=\frac{y_1(y_1+1)+y_1y_2}{y_1+y_2+1}=y_1</math>
 
 
 
 
 
  
 
==history==
 
==history==
 
* http://www.google.com/search?hl=en&tbs=tl:1&q=
 
 
 
 
 
 
 
  
 
==related items==
 
==related items==
92번째 줄: 100번째 줄:
 
* [[cluster algebra]]
 
* [[cluster algebra]]
 
* [[Nahm's equation]]
 
* [[Nahm's equation]]
* [[Central charge, L-values and dilogarithm]]
+
* [[Central charge and dilogarithm]]
 
* [[dilogarithm and dilogarithm identities]]
 
* [[dilogarithm and dilogarithm identities]]
* [[Bloch group, K-theory and dilogarithm]]
+
* [[Bloch group]]
  
 
+
==computational resource==
 +
* https://docs.google.com/file/d/0B8XXo8Tve1cxVHpWMS10SmJlSmM/edit
  
 
 
 
==encyclopedia==
 
 
* http://en.wikipedia.org/wiki/
 
* http://www.scholarpedia.org/
 
* http://www.proofwiki.org/wiki/
 
 
 
 
 
 
 
 
 
==books==
 
 
 
 
 
* [[2011년 books and articles]]
 
* http://library.nu/search?q=
 
* http://library.nu/search?q=
 
 
 
 
 
 
 
  
 
==expositions==
 
==expositions==
128번째 줄: 113번째 줄:
 
* [http://fuji.cec.yamanashi.ac.jp/%7Ering/icra14/lecture/conf/nakanishi.pdf Periodicities in cluster algebras and dilogarithm identities]
 
* [http://fuji.cec.yamanashi.ac.jp/%7Ering/icra14/lecture/conf/nakanishi.pdf Periodicities in cluster algebras and dilogarithm identities]
  
 
+
  
 
+
  
 
==articles==
 
==articles==
 +
* Nakanishi, Tomoki. “Quantum Generalized Cluster Algebras and Quantum Dilogarithms of Higher Degrees.” arXiv:1410.0584 [math], October 2, 2014. http://arxiv.org/abs/1410.0584.
 +
* Nakanishi, Tomoki. “Periodicities in Cluster Algebras and Dilogarithm Identities.” arXiv:1006.0632 [math], June 3, 2010. http://arxiv.org/abs/1006.0632.
 +
* Inoue, Rei, Osamu Iyama, Bernhard Keller, Atsuo Kuniba, and Tomoki Nakanishi. 2013. “Periodicities of T and Y-Systems, Dilogarithm Identities, and Cluster Algebras II: Types C_r, F_4, and G_2.” Publications of the Research Institute for Mathematical Sciences 49 (1): 43–85. doi:10.4171/PRIMS/96.
 +
* Inoue, Rei, Osamu Iyama, Bernhard Keller, Atsuo Kuniba, and Tomoki Nakanishi. 2013. “Periodicities of T and Y-Systems, Dilogarithm Identities, and Cluster Algebras I: Type B_r.” Publications of the Research Institute for Mathematical Sciences 49 (1): 1–42. doi:10.4171/PRIMS/95.
 +
* Nakanishi, Tomoki. “Dilogarithm Identities for Conformal Field Theories and Cluster Algebras: Simply Laced Case.” arXiv:0909.5480 [math], September 30, 2009. http://arxiv.org/abs/0909.5480.
 +
* Chapoton, Frédéric. 2005. Functional Identities for the Rogers Dilogarithm Associated to Cluster Y-Systems. Bulletin of the London Mathematical Society 37, no. 5 (October 1): 755 -760. doi:[http://dx.doi.org/10.1112/S0024609305004510 10.1112/S0024609305004510].
 +
* Caracciolo, R., F. Gliozzi, and R. Tateo. “A Topological Invariant of RG Flows in 2D Integrable Quantum Field Theories.” arXiv:hep-th/9902094, February 12, 1999. http://arxiv.org/abs/hep-th/9902094.
 +
* Frenkel, Edward, and Andras Szenes. “Thermodynamic Bethe Ansatz and Dilogarithm Identities I.” arXiv:hep-th/9506215, July 2, 1995. http://arxiv.org/abs/hep-th/9506215.
 +
* Gliozzi, F., and R. Tateo. “ADE Functional Dilogarithm Identities and Integrable Models.” Physics Letters B 348, no. 1–2 (March 30, 1995): 84–88. doi:[http://dx.doi.org/10.1016/0370-2693(95)00125-5 10.1016/0370-2693(95)00125-5].
 +
* Kuniba, A., and T. Nakanishi. “Rogers Dilogarithm in Integrable Systems.” arXiv:hep-th/9210025, October 5, 1992. http://arxiv.org/abs/hep-th/9210025.
 +
* Kuniba, Atsuo, and Tomoki Nakanishi. “Spectra in Conformal Field Theories from the Rogers Dilogarithm.” arXiv:hep-th/9206034, June 9, 1992. http://arxiv.org/abs/hep-th/9206034.
  
* [http://arxiv.org/abs/1006.0632 Periodic cluster algebras and dilogarithm identities] Tomoki Nakanishi, 2010
 
* [http://arxiv.org/abs/1001.1880 Periodicities of T and Y-systems, dilogarithm identities, and cluster algebras I: Type B_r] Rei Inoue, Osamu Iyama, Bernhard Keller, Atsuo Kuniba, Tomoki Nakanishi, 2010<br>
 
 
* [http://arxiv.org/abs/0909.5480 Dilogarithm identities for conformal field theories and cluster algebras: simply laced case] Tomoki Nakanishi, 2009<br>
 
 
* [http://arxiv.org/abs/hep-th/9506215 Thermodynamic Bethe Ansatz and Dilogarithm Identities I] Edward Frenkel, Andras Szenes, 1995<br>
 
* [http://dx.doi.org/10.1016/0370-2693%2895%2900125-5 ADE functional dilogarithm identities and integrable models] F. Gliozzi, R. Tateo, Phys. Lett. 348B (1995) 84-88.
 
 
* [http://arxiv.org/abs/hep-th/9210025 Rogers Dilogarithm in Integrable Systems] A. Kuniba, T. Nakanishi, 1992
 
* [http://arxiv.org/abs/hep-th/9206034 Spectra in Conformal Field Theories from the Rogers Dilogarithm] Atsuo Kuniba, Tomoki Nakanishi, 1992
 
 
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* [http://www.research.att.com/%7Enjas/sequences/index.html The On-Line Encyclopedia of Integer Sequences]
 
* http://functions.wolfram.com/
 
 
[[분류:개인노트]]
 
[[분류:개인노트]]
 
[[분류:cluster algebra]]
 
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[[분류:math and physics]]
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[[분류:dilogarithm]]
 +
[[분류:Y-system]]
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[[분류:migrate]]

2020년 12월 28일 (월) 05:19 기준 최신판

introduction

  • 틀:수학노트
  • \(\mathbb{Y}(X,X')\) the order of \(X\) and \(X'\) matters!
  • Caracciolo, R., F. Gliozzi, and R. Tateo in 1999 proves the functional dilogarithm identities associated ADExADE Y-systems assuming the periodicity of restricted T-system


main results

level restricted Y-system

  • Suppose that a family of positive real numbers

\[\{Y^{(a)}_m(u)\mid a\in I, 1\leq m \leq t_a\ell-1, u\in \mathbb{Z}\}\] satisfy the level \(\ell\) restricted Y-system for \(\mathfrak{g}\). Then, the following identities hold: \begin{align}\label{t:eq:DI2} \frac{6}{\pi^2}\sum_{a\in I}\sum_{m=1}^{t_a\ell-1} \sum_{u=0}^{2(h^{\vee}+\ell)-1} L\left( \frac{Y^{(a)}_m(u)}{1+Y^{(a)}_m(u)} \right) &= 2t(\ell h - h^{\vee})\mathrm{rank}\,\mathfrak{g}, \end{align} where \(h\) is the Coxeter number of \({\mathfrak g}\).

  • in simply-laced case, we get

\[ \begin{align} \frac{6}{\pi^2}\sum_{a\in I}\sum_{m=1}^{\ell-1} \sum_{u=0}^{2(h+\ell)-1} L\left( \frac{Y^{(a)}_m(u)}{1+Y^{(a)}_m(u)} \right) &= 2(\ell h - h)r=2h(\ell-1)r \end{align} \]

Y-systems for a pair of Dynkin diagrams

  • Bloch group element

\[ \sum_{(\mathbf{i},u)\in S_{+}} Y_{\mathbf{i}}(u)\wedge (1+Y_{\mathbf{i}}(u))=0\in \Lambda^2 \mathbb{Q}(y)^{\times} \] where \(S_{+}=\{(\mathbf{i},u) |0\leq u \leq 2(h+h')-1,(\mathbf{i},u)\in P_{+}\}\).

  • functional dilogarithm identity

\[ \sum_{(\mathbf{i},u)\in S_{+}}L\left(\frac{Y_\mathbf{i}(u)}{1+Y_\mathbf{i}(u)}\right)=h r r' L(1) \]


bicoloring

  • what's \(P_{+}\)?
  • We give an alternate bicoloring on the pair of Dynkin diagrams. Let us fix bipartite decompositions of \(I\) and \(I'\).
  • Let \( \mathbf{I}= I\times I'\) and \(\mathbf{I}=\mathbf{I}_{+}\sqcup \mathbf{I}_{-}\) where \(\mathbf{I}_{+}=(I_{+}\times I'_{+}) \sqcup (I_{-}\times I'_{-})\) and \(\mathbf{I}_{-}=(I_{+}\times I'_{-}) \sqcup (I_{-}\times I'_{+})\).
  • Let \(\epsilon : \mathbf{I}\to \{1,-1\}\) be the function defined by \(\epsilon(\mathbf{i})=\pm 1\) for \(\mathbf{i}\in \mathbf{I}_{\pm}\) and \(P_{\pm} =\{(\mathbf{i},u)\in \mathbf{I}\times\mathbb{Z}| \epsilon(\mathbf{i})(-1)^u=\pm 1\}\).
  • Roughly speaking, we want our alternate bicoloring interchanges their colors as \(u\in \mathbb{Z}\) changes by 1.


an example

  • compute \(\mathbb{Y}(A_2,A_1)\) explicitly
  • \(y_{m-1}y_{m+1}=y_m+1\)
  • Start with two variables \(y_1,y_2\).
  • \(y_3y_1=y_2+1\). so \(y_3=\frac{y_2+1}{y_1}\)
  • \(y_2y_4=y_3+1 \)implies \(y_4=\frac{y_3+1}{y_2}=\frac{y_1+y_2+1}{y_1y_2}\)
  • \(y_3y_5=y_4+1\) implies \(y_5=\frac{y_4+1}{y_3}= \frac{y_1+1}{y_2}\) we are getting Laurent polynomials
  • \(y_4y_6=y_5\) implies \(y_6=\frac{y_5+1}{y_4}= \frac{\frac{y_1+1}{y_2}+1}{\frac{y_1+y_2+1}{y_1y_2}}=\frac{y_1(y_1+1)+y_1y_2}{y_1+y_2+1}=y_1\)
  • rank 2 cluster algebra


observations

  • we saw that \[S=\left\{x,y,\frac{y+1}{x},\frac{x+y+1}{x y},\frac{x+1}{y}\right\}\] forms a half-period of \(\mathbb{Y}(A_2,A_1)\).
  • So we have \(r=2,h=3\) and \(r'=1,h'=2\).
  • They are all Laurent polynomials in \(x\) and \(y\).


dilogarithm identities

  • From this, one can get functional dilogarithm identities

\begin{align} &\sum_{a\in S}L\left(\frac{a}{1+a}\right) \notag \\ =& L\left(\frac{x}{1+x}\right)+L\left(\frac{y}{1+y}\right)+L\left(\frac{1+y}{x (1+\frac{1+y}{x})}\right)+L\left(\frac{1+x+y}{x y (1+\frac{1+x+y}{x y})}\right)+L\left(\frac{1+x}{(1+\frac{1+x}{y}) y}\right) \notag \\ =& L\left(\frac{x}{x+1}\right)+L\left(\frac{y}{y+1}\right)+L\left(\frac{y+1}{x+y+1}\right)+L\left(\frac{x+y+1}{x y+x+y+1}\right)+L\left(\frac{x+1}{x+y+1}\right) \notag \\ =&3L(1)=\frac{\pi^2}{2} \notag \end{align} and \begin{align} &\sum_{a\in S}L\left(\frac{1}{1+a}\right) \notag \\ =& L\left(\frac{1}{x+1}\right)+L\left(\frac{1}{y+1}\right)+L\left(\frac{1}{\frac{y+1}{x}+1}\right)+L\left(\frac{1}{\frac{x+y+1}{x y}+1}\right)+L\left(\frac{1}{\frac{x+1}{y}+1}\right) \notag \\ =& L\left(\frac{1}{x+1}\right)+L\left(\frac{1}{y+1}\right)+L\left(\frac{x}{x+y+1}\right)+L\left(\frac{x y}{x y+x+y+1}\right)+L\left(\frac{y}{x+y+1}\right) \notag \\ =&2L(1)=\frac{\pi^2}{3} \notag. \end{align}


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  • Nakanishi, Tomoki. “Quantum Generalized Cluster Algebras and Quantum Dilogarithms of Higher Degrees.” arXiv:1410.0584 [math], October 2, 2014. http://arxiv.org/abs/1410.0584.
  • Nakanishi, Tomoki. “Periodicities in Cluster Algebras and Dilogarithm Identities.” arXiv:1006.0632 [math], June 3, 2010. http://arxiv.org/abs/1006.0632.
  • Inoue, Rei, Osamu Iyama, Bernhard Keller, Atsuo Kuniba, and Tomoki Nakanishi. 2013. “Periodicities of T and Y-Systems, Dilogarithm Identities, and Cluster Algebras II: Types C_r, F_4, and G_2.” Publications of the Research Institute for Mathematical Sciences 49 (1): 43–85. doi:10.4171/PRIMS/96.
  • Inoue, Rei, Osamu Iyama, Bernhard Keller, Atsuo Kuniba, and Tomoki Nakanishi. 2013. “Periodicities of T and Y-Systems, Dilogarithm Identities, and Cluster Algebras I: Type B_r.” Publications of the Research Institute for Mathematical Sciences 49 (1): 1–42. doi:10.4171/PRIMS/95.
  • Nakanishi, Tomoki. “Dilogarithm Identities for Conformal Field Theories and Cluster Algebras: Simply Laced Case.” arXiv:0909.5480 [math], September 30, 2009. http://arxiv.org/abs/0909.5480.
  • Chapoton, Frédéric. 2005. Functional Identities for the Rogers Dilogarithm Associated to Cluster Y-Systems. Bulletin of the London Mathematical Society 37, no. 5 (October 1): 755 -760. doi:10.1112/S0024609305004510.
  • Caracciolo, R., F. Gliozzi, and R. Tateo. “A Topological Invariant of RG Flows in 2D Integrable Quantum Field Theories.” arXiv:hep-th/9902094, February 12, 1999. http://arxiv.org/abs/hep-th/9902094.
  • Frenkel, Edward, and Andras Szenes. “Thermodynamic Bethe Ansatz and Dilogarithm Identities I.” arXiv:hep-th/9506215, July 2, 1995. http://arxiv.org/abs/hep-th/9506215.
  • Gliozzi, F., and R. Tateo. “ADE Functional Dilogarithm Identities and Integrable Models.” Physics Letters B 348, no. 1–2 (March 30, 1995): 84–88. doi:10.1016/0370-2693(95)00125-5.
  • Kuniba, A., and T. Nakanishi. “Rogers Dilogarithm in Integrable Systems.” arXiv:hep-th/9210025, October 5, 1992. http://arxiv.org/abs/hep-th/9210025.
  • Kuniba, Atsuo, and Tomoki Nakanishi. “Spectra in Conformal Field Theories from the Rogers Dilogarithm.” arXiv:hep-th/9206034, June 9, 1992. http://arxiv.org/abs/hep-th/9206034.