A Faster Approximation Algorithm for the Gibbs Partition Function

Vladimir Kolmogorov
Proceedings of the 31st Conference On Learning Theory, PMLR 75:228-249, 2018.

Abstract

We consider the problem of estimating the partition function Z(β)=xexp(βH(x)) of a Gibbs distribution with a Hamilton H(), or more precisely the logarithm of the ratio q=lnZ(0)/Z(β). It has been recently shown how to approximate q with high probability assuming the existence of an oracle that produces samples from the Gibbs distribution for a given parameter value in [0,β]. The current best known approach due to Huber (2015) uses O(qlnn[lnq+lnlnn+ε2]) oracle calls on average where ε is the desired accuracy of approximation and H() is assumed to lie in {0}[1,n]. We improve the complexity to O(qlnnε2) oracle calls. We also show that the same complexity can be achieved if exact oracles are replaced with approximate sampling oracles that are within O(ε2qlnn) variation distance from exact oracles. Finally, we prove a lower bound of Ω(qε2) oracle calls under a natural model of computation.

Cite this Paper


BibTeX
@InProceedings{pmlr-v75-kolmogorov18a, title = {A Faster Approximation Algorithm for the {G}ibbs Partition Function}, author = {Kolmogorov, Vladimir}, booktitle = {Proceedings of the 31st Conference On Learning Theory}, pages = {228--249}, year = {2018}, editor = {Bubeck, Sébastien and Perchet, Vianney and Rigollet, Philippe}, volume = {75}, series = {Proceedings of Machine Learning Research}, month = {06--09 Jul}, publisher = {PMLR}, pdf = {http://proceedings.mlr.press/v75/kolmogorov18a/kolmogorov18a.pdf}, url = {https://proceedings.mlr.press/v75/kolmogorov18a.html}, abstract = { We consider the problem of estimating the partition function $Z(\beta)=\sum_x \exp(-\beta H(x))$ of a Gibbs distribution with a Hamilton $H(\cdot)$, or more precisely the logarithm of the ratio $q=\ln Z(0)/Z(\beta)$. It has been recently shown how to approximate $q$ with high probability assuming the existence of an oracle that produces samples from the Gibbs distribution for a given parameter value in $[0,\beta]$. The current best known approach due to Huber (2015) uses $O(q\ln n\cdot[\ln q + \ln \ln n+\varepsilon^{-2}])$ oracle calls on average where $\varepsilon$ is the desired accuracy of approximation and $H(\cdot)$ is assumed to lie in $\{0\}\cup[1,n]$. We improve the complexity to $O(q\ln n\cdot\varepsilon^{-2})$ oracle calls. We also show that the same complexity can be achieved if exact oracles are replaced with approximate sampling oracles that are within $O(\frac{\varepsilon^2}{q\ln n})$ variation distance from exact oracles. Finally, we prove a lower bound of $\Omega(q\cdot \varepsilon^{-2})$ oracle calls under a natural model of computation. } }
Endnote
%0 Conference Paper %T A Faster Approximation Algorithm for the Gibbs Partition Function %A Vladimir Kolmogorov %B Proceedings of the 31st Conference On Learning Theory %C Proceedings of Machine Learning Research %D 2018 %E Sébastien Bubeck %E Vianney Perchet %E Philippe Rigollet %F pmlr-v75-kolmogorov18a %I PMLR %P 228--249 %U https://proceedings.mlr.press/v75/kolmogorov18a.html %V 75 %X We consider the problem of estimating the partition function $Z(\beta)=\sum_x \exp(-\beta H(x))$ of a Gibbs distribution with a Hamilton $H(\cdot)$, or more precisely the logarithm of the ratio $q=\ln Z(0)/Z(\beta)$. It has been recently shown how to approximate $q$ with high probability assuming the existence of an oracle that produces samples from the Gibbs distribution for a given parameter value in $[0,\beta]$. The current best known approach due to Huber (2015) uses $O(q\ln n\cdot[\ln q + \ln \ln n+\varepsilon^{-2}])$ oracle calls on average where $\varepsilon$ is the desired accuracy of approximation and $H(\cdot)$ is assumed to lie in $\{0\}\cup[1,n]$. We improve the complexity to $O(q\ln n\cdot\varepsilon^{-2})$ oracle calls. We also show that the same complexity can be achieved if exact oracles are replaced with approximate sampling oracles that are within $O(\frac{\varepsilon^2}{q\ln n})$ variation distance from exact oracles. Finally, we prove a lower bound of $\Omega(q\cdot \varepsilon^{-2})$ oracle calls under a natural model of computation.
APA
Kolmogorov, V.. (2018). A Faster Approximation Algorithm for the Gibbs Partition Function. Proceedings of the 31st Conference On Learning Theory, in Proceedings of Machine Learning Research 75:228-249 Available from https://proceedings.mlr.press/v75/kolmogorov18a.html.

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