A tensor-train multidimensional inverse Laplace transform
Pith reviewed 2026-06-28 00:08 UTC · model grok-4.3
The pith
Tensor-train formulation computes multidimensional inverse Laplace transforms in polynomial time under low-rank assumptions.
A machine-rendered reading of the paper's core claim, the machinery that carries it, and where it could break.
Core claim
The multidimensional inverse Laplace transform can be formulated using a tensor-train approximation of the transformed function on the complex quadrature grid, followed by inversion via a sequence of tensor contractions, reducing computational cost from exponential to polynomial in the dimension when bond dimensions remain bounded.
What carries the argument
The tensor-train (TT) approximation on the quadrature grid, where the inversion is carried out by successive tensor contractions.
If this is right
- Computation becomes feasible for higher-dimensional problems in applied mathematics and physics.
- Error estimations are available due to the approximation properties of tensor trains.
- The approach applies to distributions such as multivariate normal-inverse Gaussian, Wishart, and correlated Gamma-type.
- Only a small number of tunable parameters are needed for the method.
Where Pith is reading between the lines
- Similar tensor-train techniques could extend to other integral transforms that suffer from the curse of dimensionality.
- Testing on problems where low-rank structure breaks down would reveal the method's limits.
- Integration with existing low-rank tensor libraries might accelerate adoption in scientific computing.
Load-bearing premise
The transformed function on the complex quadrature grid admits a low-rank tensor-train representation whose bond dimensions remain bounded.
What would settle it
A counterexample distribution where the required tensor-train bond dimensions grow exponentially with the number of dimensions would show that the polynomial scaling does not hold in general.
Figures
read the original abstract
Laplace transforms and their numerical inverses arise throughout applied mathematics, physics, finance, and probability theory. Numerical inversion, however, quickly becomes intractable in high dimensions because the number of quadrature evaluations grows exponentially with dimension. We develop a tensor train (TT) formulation of the multidimensional inverse Laplace transform. The method constructs a TT approximation of the transformed function on the complex quadrature grid and then performs the inversion through a sequence of tensor contractions. Under suitable low-rank assumptions, this reduces the computational cost from exponential to polynomial in the dimension, provided that the relevant bond dimensions remain bounded. The method has only a small number of tunable parameters and admits error estimations. We demonstrate its performance in numerical experiments, benchmarked against Monte Carlo estimates and exact references, for multivariate normal-inverse Gaussian, Wishart, and correlated Gamma-type distributions.
Editorial analysis
A structured set of objections, weighed in public.
Referee Report
Summary. The paper develops a tensor-train (TT) formulation of the multidimensional inverse Laplace transform. It constructs a TT approximation to the transformed function evaluated on a complex quadrature grid and performs the inversion via a sequence of tensor contractions. Under the assumption that the relevant TT bond dimensions remain bounded, the approach is claimed to reduce the cost from exponential to polynomial in the dimension. The method is equipped with a small number of tunable parameters and error estimates, and is demonstrated numerically on the multivariate normal-inverse Gaussian, Wishart, and correlated Gamma distributions, with comparisons to Monte Carlo and exact references.
Significance. If the low-rank TT structure with dimension-independent bond dimensions holds for the target distributions, the work would supply a practical, parameter-light route to high-dimensional inverse Laplace transforms that appear in probability, finance, and physics. The explicit error estimates and the reduction to tensor contractions are concrete strengths; the numerical benchmarks against independent references further support usability when the rank condition is met.
major comments (2)
- [Abstract / §1] Abstract and §1: The central claim that the method achieves polynomial scaling in dimension rests on the transformed function admitting a TT representation whose bond dimensions remain bounded independently of d. No general argument, a priori bound, or scaling analysis is supplied showing that the ranks stay controlled for the Laplace transforms of the multivariate normal-inverse Gaussian, Wishart, or correlated Gamma distributions as dimension grows. This assumption is load-bearing for the complexity reduction.
- [Numerical experiments] Numerical experiments section: While benchmarks against Monte Carlo and exact references are reported, the experiments do not include a systematic study of TT rank growth versus dimension d for the cited distributions. Without such data it is impossible to confirm that the polynomial-cost regime is actually attained.
minor comments (2)
- [§2] Notation for the quadrature nodes and weights in the complex plane should be introduced with an explicit reference to the one-dimensional inversion formula being discretized.
- [§3] The statement that the method 'admits error estimations' would be strengthened by a short theorem or proposition collecting the relevant bounds rather than leaving them implicit in the text.
Simulated Author's Rebuttal
We thank the referee for the careful reading and constructive comments on our manuscript. We address the major comments point by point below, clarifying the scope of our claims and indicating where revisions will be made.
read point-by-point responses
-
Referee: [Abstract / §1] Abstract and §1: The central claim that the method achieves polynomial scaling in dimension rests on the transformed function admitting a TT representation whose bond dimensions remain bounded independently of d. No general argument, a priori bound, or scaling analysis is supplied showing that the ranks stay controlled for the Laplace transforms of the multivariate normal-inverse Gaussian, Wishart, or correlated Gamma distributions as dimension grows. This assumption is load-bearing for the complexity reduction.
Authors: The manuscript explicitly qualifies the complexity claim as holding 'under suitable low-rank assumptions' and 'provided that the relevant bond dimensions remain bounded.' We do not claim or attempt to prove that the TT ranks are bounded independently of dimension for arbitrary distributions or even for the specific families considered; the paper develops the TT formulation of the inverse Laplace transform and shows how it yields polynomial cost when the low-rank structure is present. The numerical experiments provide supporting evidence that moderate ranks are observed for the tested distributions and dimensions. A general theoretical bound on rank growth is an interesting open question but is outside the scope of this work. revision: no
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Referee: [Numerical experiments] Numerical experiments section: While benchmarks against Monte Carlo and exact references are reported, the experiments do not include a systematic study of TT rank growth versus dimension d for the cited distributions. Without such data it is impossible to confirm that the polynomial-cost regime is actually attained.
Authors: We agree that a systematic examination of TT rank growth versus dimension would make the numerical validation more complete. In the revised manuscript we will add figures and tables reporting the observed TT ranks (maximum bond dimension) as a function of dimension d for each of the three distribution families, using the same parameter settings as the existing experiments. This will directly illustrate whether the ranks remain controlled in the regimes where the method is demonstrated. revision: yes
- A general argument or a priori bound demonstrating that the TT bond dimensions remain bounded independently of dimension for the Laplace transforms of the normal-inverse Gaussian, Wishart, and correlated Gamma distributions.
Circularity Check
No significant circularity; derivation is self-contained
full rationale
The paper develops a TT-based numerical method for multidimensional inverse Laplace transforms by constructing a low-rank approximation on a quadrature grid followed by tensor contractions. The claimed complexity reduction is explicitly conditional on the external assumption that bond dimensions remain bounded, which is not derived or fitted within the paper itself. No equations reduce a result to its own inputs by construction, no parameters are fitted and then relabeled as predictions, and no load-bearing steps rely on self-citations or imported uniqueness theorems. The approach rests on standard tensor-train algebra and quadrature, making the central formulation independent of the target result.
Axiom & Free-Parameter Ledger
free parameters (1)
- bond dimensions
axioms (1)
- domain assumption Existence of low-rank TT structure on the quadrature grid
Reference graph
Works this paper leans on
-
[1]
The fourier- series method for inverting transforms of probability distributions.Queueing systems, 10(1):5–87, 1992
Joseph Abate and Ward Whitt. The fourier- series method for inverting transforms of probability distributions.Queueing systems, 10(1):5–87, 1992
1992
-
[2]
Joseph Abate, Gagan L. Choudhury, and Ward Whitt. Numerical inversion of mul- tidimensional laplace transforms by the laguerre method.Performance Evaluation, 31(3):229–243, 1998. ISSN 0166-5316. DOI: https://doi.org/10.1016/S0166- 5316(97)00002-3. URLhttps: //www.sciencedirect.com/science/ article/pii/S0166531697000023
-
[3]
Lucas Arenstein and Michael Kastoryano. Full grid solution for multi-asset options pricing with tensor networks.arXiv preprint arXiv:2601.00009, 2025
arXiv 2025
-
[4]
Lucas Arenstein, Martin Mikkelsen, and Michael Kastoryano. Fast and flexi- ble quantum-inspired differential equation solvers with data integration.arXiv preprint arXiv:2505.17046, 2025
arXiv 2025
-
[5]
Normal inverse gaus- sian processes and the modelling of stock re- turns
Ole Barndorff-Nielsen. Normal inverse gaus- sian processes and the modelling of stock re- turns. Workingpaper, Department of Math- ematical Sciences, Aarhus University, Den- mark, 1994
1994
-
[6]
Normal variance-mean mixtures and z distributions.International Statistical Review/Revue Internationale de Statistique, pages 145–159, 1982
Ole Barndorff-Nielsen, John Kent, and Michael Sørensen. Normal variance-mean mixtures and z distributions.International Statistical Review/Revue Internationale de Statistique, pages 145–159, 1982
1982
-
[7]
Protes: prob- abilistic optimization with tensor sampling
Anastasiia Batsheva, Andrei Chertkov, Gleb Ryzhakov, andIvanOseledets. Protes: prob- abilistic optimization with tensor sampling. Advances in Neural Information Processing Systems, 36:808–823, 2023
2023
-
[8]
Jielun Chen and Michael Lindsey. Direct interpolative construction of the discrete fourier transform as a matrix product oper- ator, 2024. URLhttps://arxiv.org/abs/ 2404.03182
arXiv 2024
-
[9]
Quantum fourier transform has small entanglement.PRX Quantum, 4(4):040318, 2023
JielunChen, EMStoudenmire, andStevenR White. Quantum fourier transform has small entanglement.PRX Quantum, 4(4):040318, 2023
2023
-
[10]
Gagan Choudhury, David Lucantoni, and Ward Whitt. Multidimensional transform inversion with applications to the transient m/g/1 queue.Annals of Applied Probability, 4, 08 1994. DOI: 10.1214/aoap/1177004968
-
[11]
Gagan L. Choudhury and Ward Whitt. Probabilistic scaling for the numerical in- version of nonprobability transforms.IN- FORMS Journal on Computing, 9(2):175– 184, 1997. DOI: 10.1287/ijoc.9.2.175. URLhttps://doi.org/10.1287/ijoc.9. 2.175
-
[12]
Tay- lor series approach to functional approxima- tion for inversion of laplace transforms.Elec- tronics Letters, 22(23):1219–1221, 1986
Huang-Yuan Chung and York-Yih Sun. Tay- lor series approach to functional approxima- tion for inversion of laplace transforms.Elec- tronics Letters, 22(23):1219–1221, 1986
1986
-
[13]
Springer Science & Business Media, 2007
Alan M Cohen.Numerical methods for Laplace transform inversion, volume 5. Springer Science & Business Media, 2007
2007
-
[14]
Parallel talbot’s al- gorithm for distributed memory machines
Maria Assunta De Rosa, Giulio Giunta, and Mariarosaria Rizzardi. Parallel talbot’s al- gorithm for distributed memory machines. Parallel computing, 21(5):783–801, 1995
1995
-
[15]
Superfast Fourier transform using QTT approximation.J
Sergey Dolgov, Boris Khoromskij, and Dmitry Savostyanov. Superfast Fourier transform using QTT approximation.J. Fourier Anal. Appl., 18(5):915–953, 2012. ISSN 1531-5851. DOI: 10.1007/s00041-012- 9227-4. URLhttps://doi.org/10.1007/ s00041-012-9227-4
-
[16]
Sergey Dolgov, Boris N Khoromskij, Alexan- der Litvinenko, and Hermann G Matthies. Polynomial chaos expansion of random co- efficients and the solution of stochastic par- tial differential equations in the tensor train format.SIAM/ASA Journal on Uncertainty Quantification, 3(1):1109–1135, 2015
2015
-
[17]
Approxi- mation and sampling of multivariate prob- ability distributions in the tensor train de- composition.Statistics and Computing, 30 (3):603–625, 2020
Sergey Dolgov, Karim Anaya-Izquierdo, Colin Fox, and Robert Scheichl. Approxi- mation and sampling of multivariate prob- ability distributions in the tensor train de- composition.Statistics and Computing, 30 (3):603–625, 2020
2020
-
[18]
Sergey Dolgov, Dante Kalise, and Karl K. Kunisch. Tensor decomposition meth- ods for high-dimensional hamilton–jacobi– bellman equations.SIAM Journal on Scien- tific Computing, 43(3):A1625–A1650, 2021. DOI: 10.1137/19M1305136. URLhttps: //doi.org/10.1137/19M1305136
-
[19]
Dean G Duffy. On the numerical inversion of laplace transforms: comparison of three new methods on characteristic problems from ap- 16 plications.ACM Transactions on Mathemat- ical Software (TOMS), 19(3):333–359, 1993
1993
-
[20]
Numerical inversion of laplace transforms using contour methods.Interna- tional journal of computer mathematics, 49 (1-2):93–105, 1993
GA Evans. Numerical inversion of laplace transforms using contour methods.Interna- tional journal of computer mathematics, 49 (1-2):93–105, 1993
1993
-
[21]
The inverse gaussian distribution and its statis- tical application—a review.Journal of the Royal Statistical Society Series B: Statistical Methodology, 40(3):263–275, 1978
J Leroy Folks and Raj S Chhikara. The inverse gaussian distribution and its statis- tical application—a review.Journal of the Royal Statistical Society Series B: Statistical Methodology, 40(3):263–275, 1978
1978
-
[22]
S. A. Goreinov, I. V. Oseledets, D. V. Savostyanov, E. E. Tyrtyshnikov, and N. L. Zamarashkin.How to Find a Good Submatrix, pages 247–256. World Scientific Publishing, 2010. DOI: 10.1142/9789812836021_0015. URL https://www.worldscientific.com/doi/ abs/10.1142/9789812836021_0015
-
[23]
The maximal-volume concept in approximation by low-rank matrices.Contemporary Math- ematics, 268:47–51, 2001
Sergei Goreinov and E Tyrtyshnikov. The maximal-volume concept in approximation by low-rank matrices.Contemporary Math- ematics, 268:47–51, 2001
2001
-
[24]
PhDthesis, Department of Applied Mathematics, Impe- rial College London, 1955
John Stephen Green.The calculation of the time-responses of linear systems. PhDthesis, Department of Applied Mathematics, Impe- rial College London, 1955
1955
-
[25]
The nor- mal inverse gaussian distribution as a flex- ible model for heavy tailed processes
A Hanssen and TA Øigård. The nor- mal inverse gaussian distribution as a flex- ible model for heavy tailed processes. In Proc. IEEE-EURASIP Workshop on Nonlin- ear Signal and Image Processing, June 3-6, Baltimore, Maryland, USA, 2001
2001
-
[26]
Generic construction of ef- ficient matrix product operators.Physical Review B, 95(3):035129, 2017
Claudius Hubig, Ian P McCulloch, and Ul- rich Schollwöck. Generic construction of ef- ficient matrix product operators.Physical Review B, 95(3):035129, 2017
2017
-
[27]
Numerical quadrature of fourier transform integrals
H Hurwitz and PF Zweifel. Numerical quadrature of fourier transform integrals. Mathematics of Computation, 10(55):140– 149, 1956
1956
-
[28]
Noufal Jaseem, Sergi Ramos-Calderer, Dingzu Wang, José Ignacio Latorre, Dario Poletti, et al. Quantum-inspired algorithms beyond unitary circuits: the laplace trans- form.arXiv preprint arXiv:2601.17724, 2026
arXiv 2026
-
[29]
B. Khoromskij. O(dlogn)-quantics approxi- mation ofn−dtensors in high-dimensional numerical modeling.Constructive Approxi- mation - CONSTR APPROX, 34, 01 2009. DOI: 10.1007/s00365-011-9131-1
-
[30]
Gérard Letac and Hélène Massam. The noncentral wishart as an exponential family, and its moments.Journal of Multivariate Analysis, 99(7):1393– 1417, 2008. ISSN 0047-259X. DOI: https://doi.org/10.1016/j.jmva.2008.04.006. URLhttps://www.sciencedirect. com/science/article/pii/ S0047259X08001139. Special Issue: Mul- tivariate Distributions, Inference and Appl...
-
[31]
Multiscale interpola- tive construction of quantized tensor trains
Michael Lindsey. Multiscale interpola- tive construction of quantized tensor trains. arXiv preprint arXiv:2311.12554, 2023
arXiv 2023
-
[32]
Numerical laplace transform inversion of a function arising in viscoelas- ticity.Journal of Computational Physics, 10 (2):224–231, 1972
IM Longman. Numerical laplace transform inversion of a function arising in viscoelas- ticity.Journal of Computational Physics, 10 (2):224–231, 1972
1972
-
[33]
J. N. Lyness and G. Giunta. A modifica- tion of the weeks method for numerical in- version of the laplace transform.Mathemat- ics of Computation, 47(175):313–322, 1986. ISSN 00255718, 10886842. URLhttp:// www.jstor.org/stable/2008097
arXiv 1986
-
[34]
Tensortrainnumerics.jl, June 2026
Mikkelsen Martin. Tensortrainnumerics.jl, June 2026. URLhttps://doi.org/10. 5281/zenodo.20514254
2026
-
[35]
Inversion of the multi- dimensional laplace transform-expansion by laguerre series.Zeitschrift für angewandte Mathematik und Physik ZAMP, 46(5):793– 806, 1995
MV Moorthy. Inversion of the multi- dimensional laplace transform-expansion by laguerre series.Zeitschrift für angewandte Mathematik und Physik ZAMP, 46(5):793– 806, 1995
1995
-
[36]
Ten- sorizing neural networks.Advances in neural information processing systems, 28, 2015
Alexander Novikov, Dmitrii Podoprikhin, Anton Osokin, and Dmitry P Vetrov. Ten- sorizing neural networks.Advances in neural information processing systems, 28, 2015
2015
-
[37]
The multivariate normal inverse gaussian heavy-tailed distribution; simulation and estimation
Tor Arne Oigard, Tor Arne Øigård, and Alfred Hanssen. The multivariate normal inverse gaussian heavy-tailed distribution; simulation and estimation. In2002 IEEE In- ternational Conference on Acoustics, Speech, and Signal Processing, volume 2, pages II–
-
[38]
Em-estimation and modeling of heavy-tailed processes with the multivariate 17 normal inverse gaussian distribution.Signal processing, 85(8):1655–1673, 2005
Tor Arne Øigård, Alfred Hanssen, Roy Edgar Hansen, and Fred Godtlieb- sen. Em-estimation and modeling of heavy-tailed processes with the multivariate 17 normal inverse gaussian distribution.Signal processing, 85(8):1655–1673, 2005
2005
-
[39]
I. V. Oseledets. Tensor-train decom- position.SIAM Journal on Scientific Computing, 33(5):2295–2317, 2011. DOI: 10.1137/090752286. URLhttps://doi. org/10.1137/090752286
-
[40]
Ivan Oseledets and Eugene Tyrtyshnikov. Tt - cross approximation for multidimensional arrays.Linear Algebra and its Applications, 432(1):70–88, 2010. ISSN 0024-3795. DOI: https://doi.org/10.1016/j.laa.2009.07.024. URLhttps://www.sciencedirect. com/science/article/pii/ S0024379509003747
-
[41]
Matrix product state representations.arXiv preprint quant-ph/0608197, 2006
David Perez-Garcia, Frank Verstraete, Michael M Wolf, and J Ignacio Cirac. Matrix product state representations.arXiv preprint quant-ph/0608197, 2006
Pith/arXiv arXiv 2006
-
[42]
Emil L. Post. Generalized differentiation. Transactions of the American Mathemat- ical Society, 32(4):723–781, 1930. ISSN 00029947, 10886850. URLhttp://www. jstor.org/stable/1989348
arXiv 1930
-
[43]
Error analysis of tensor-train cross approximation.Advances in neural infor- mation processing systems, 35:14236–14249, 2022
Zhen Qin, Alexander Lidiak, Zhexuan Gong, Gongguo Tang, Michael B Wakin, and Zhi- hui Zhu. Error analysis of tensor-train cross approximation.Advances in neural infor- mation processing systems, 35:14236–14249, 2022
2022
-
[44]
Solving high-dimensional parabolic pdes using the tensor train format
Lorenz Richter, Leon Sallandt, and Nikolas Nüsken. Solving high-dimensional parabolic pdes using the tensor train format. InInter- national Conference on Machine Learning, pages 8998–9009. PMLR, 2021
2021
-
[45]
Orthogonal polynomials arising in the numerical evaluation of inverse laplace transforms.Mathematics of Compu- tation, 9(52):164–177, 1955
Herbert E Salzer. Orthogonal polynomials arising in the numerical evaluation of inverse laplace transforms.Mathematics of Compu- tation, 9(52):164–177, 1955
1955
-
[46]
Fast adaptive interpolation of multi- dimensional arrays in tensor train format
Dmitry Savostyanov and Ivan Oseledets. Fast adaptive interpolation of multi- dimensional arrays in tensor train format. InThe 2011 International Workshop on Multidimensional (nD) Systems, pages 1–8,
2011
-
[47]
DOI: 10.1109/nDS.2011.6076873
-
[48]
Dmitry V. Savostyanov. Quasioptimality of maximum-volume cross interpolation of tensors.Linear Algebra and its Applications, 458:217–244, 2014. ISSN 0024-3795. DOI: https://doi.org/10.1016/j.laa.2014.06.006. URLhttps://www.sciencedirect. com/science/article/pii/ S0024379514003711
-
[49]
Numerical inversion of laplace transforms.Communications of the ACM, 3(3):171–173, 1960
Louis A Schmittroth. Numerical inversion of laplace transforms.Communications of the ACM, 3(3):171–173, 1960
1960
-
[50]
The density-matrix renormalization group in the age of matrix product states.Annals of physics, 326(1): 96–192, 2011
Ulrich Schollwöck. The density-matrix renormalization group in the age of matrix product states.Annals of physics, 326(1): 96–192, 2011
2011
-
[51]
Best rational function approxi- mation to laplace transform inversion using a window function.Journal of Computa- tional and Applied Mathematics, 2(3):187– 194, 1976
Avram Sidi. Best rational function approxi- mation to laplace transform inversion using a window function.Journal of Computa- tional and Applied Mathematics, 2(3):187– 194, 1976
1976
-
[52]
Numerical inversion of multidimensional laplace trans- form.Proceedings of the IEEE, 63(11):1627– 1628, 2005
K Singhal, J Vlach, and M Vlach. Numerical inversion of multidimensional laplace trans- form.Proceedings of the IEEE, 63(11):1627– 1628, 2005
2005
-
[53]
Konstantin Sozykin, Andrei Chertkov, Ro- man Schutski, Anh-Huy Phan, Andrzej S Ci- chocki, and Ivan Oseledets. Ttopt: A max- imum volume quantized tensor train-based optimization and its application to reinforce- ment learning.Advances in neural infor- mation processing systems, 35:26052–26065, 2022
2022
-
[54]
CreditSuisse, 1997
Credit Suisse.CreditRisk+: A credit risk management framework. CreditSuisse, 1997
1997
-
[55]
The accurate numerical inver- sion of laplace transforms.IMA Journal of Applied Mathematics, 23(1):97–120, 1979
Alan Talbot. The accurate numerical inver- sion of laplace transforms.IMA Journal of Applied Mathematics, 23(1):97–120, 1979
1979
-
[56]
Tensor-train nu- merical integration of multivariate functions with singularities.Lobachevskii Journal of Mathematics, 42(7):1608–1621, 2021
Lev I Vysotsky, Alexander V Smirnov, and Eugene E Tyrtyshnikov. Tensor-train nu- merical integration of multivariate functions with singularities.Lobachevskii Journal of Mathematics, 42(7):1608–1621, 2021
2021
-
[57]
Learning multidimensional fourier series with tensor trains
Sander Wahls, Visa Koivunen, H Vincent Poor, and Michel Verhaegen. Learning multidimensional fourier series with tensor trains. In2014 IEEE Global Conference on Signal and Information Processing (Global- SIP), pages 394–398. IEEE, 2014
2014
-
[58]
The laplace trans- form.Princeton University Press, 1941
David Vernon Widder. The laplace trans- form.Princeton University Press, 1941. ISSN 00029947, 10886850
1941
-
[59]
Zheng Zhang, Xiu Yang, Ivan V Oseledets, George E Karniadakis, and Luca Daniel. En- abling high-dimensional hierarchical uncer- tainty quantification by anova and tensor- train decomposition.IEEE Transactions on 18 Computer-Aided Design of Integrated Cir- cuits and Systems, 34(1):63–76, 2014. A Two-dimensional inversion with continuous variable The follow...
2014
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