A Musielak-Orlicz approach for modeling uncertainties in long-memory processes
Pith reviewed 2026-05-13 21:37 UTC · model grok-4.3
The pith
Musielak-Orlicz spaces enable well-posed optimization of cumulant bounds for supOU processes under uncertainty in reversion and Levy measures, where Kullback-Leibler divergence fails.
A machine-rendered reading of the paper's core claim, the machinery that carries it, and where it could break.
Core claim
The paper establishes that state-dependent divergence functions defined on Musielak-Orlicz spaces allow formulation of optimization problems whose solutions give the sharpest upper and lower bounds on cumulants of supOU processes when the reversion and Levy measures are allowed to vary inside a prescribed uncertainty set, and that these problems admit solutions under stated conditions while classical divergences such as Kullback-Leibler do not.
What carries the argument
State-dependent divergence functions on Musielak-Orlicz spaces that define uncertainty sets for the optimization problems determining cumulant bounds.
If this is right
- Upper and lower cumulant bounds become computable for any supOU process whose uncertainty set satisfies the given conditions.
- Sufficient conditions guarantee existence of solutions to the optimization problems.
- The same construction applies directly to environmental time-series modeling such as streamflow discharge.
- The framework supplies a consistent way to propagate measure uncertainty into cumulant estimates without relying on Kullback-Leibler divergence.
Where Pith is reading between the lines
- The same divergence construction could be tested on other superposition-based long-memory models to check whether the well-posedness carries over.
- Numerical solution schemes for the resulting infinite-dimensional optimizations would be needed before routine use in large-scale forecasting.
- Tighter cumulant bounds may improve downstream risk calculations in hydrology or finance when reversion and jump intensities are only partially known.
Load-bearing premise
Uncertainties in supOU processes can be represented as distortions in reversion and Levy measures such that state-dependent divergence functions on Musielak-Orlicz spaces produce well-posed optimization problems for cumulant bounds.
What would settle it
A concrete supOU process and uncertainty set for which the resulting optimization problem either becomes ill-posed or returns infinite cumulant bounds would falsify the claim that the Musielak-Orlicz construction resolves the difficulties.
Figures
read the original abstract
This paper proposes a novel mathematical framework for modeling uncertainties in supOU processes, a common model for long-memory phenomena. We address uncertainties as distortions in reversion and Levy measures, evaluating them simultaneously via state-dependent divergence functions on Musielak-Orlicz spaces. The core of our approach involves solving optimization problems to determine the upper- and lower-bounds of cumulants under a prescribed uncertainty set. Notably, we demonstrate that while classical measures like Kullback-Leibler divergence fail in this context, Musielak-Orlicz spaces effectively resolve these issues. Along with providing sufficient conditions for the well-posedness of these optimizations, we demonstrate the framework's practical utility through a water environmental application, modeling streamflow discharge. This work offers both a theoretical advancement and a robust tool for long-memory process analysis.
Editorial analysis
A structured set of objections, weighed in public.
Referee Report
Summary. The paper proposes a framework for modeling uncertainties in supOU processes by representing them as distortions in the reversion and Lévy measures. These uncertainties are quantified simultaneously via state-dependent divergence functions defined on Musielak-Orlicz spaces. The central technical step is the formulation and solution of optimization problems that yield upper and lower bounds on cumulants under a prescribed uncertainty set. The manuscript asserts that the Kullback-Leibler divergence fails to produce well-posed problems in this setting while the Musielak-Orlicz construction succeeds, supplies sufficient conditions guaranteeing well-posedness, and illustrates the method on a streamflow-discharge application.
Significance. If the well-posedness conditions and the claimed superiority over KL divergence are rigorously established, the work supplies a concrete, application-oriented tool for bounding cumulants of long-memory processes under model uncertainty. The streamflow example indicates immediate relevance to environmental modeling, and the provision of explicit sufficient conditions for the optimization problems is a positive feature that could facilitate adoption by practitioners.
minor comments (3)
- The abstract states that 'sufficient conditions for the well-posedness of these optimizations' are supplied; the introduction or the statement of the main theorem should explicitly list or reference these conditions so that readers can locate them without searching the entire text.
- In the streamflow application, the manuscript should report the concrete data source, the size of the uncertainty set, and quantitative comparison (e.g., bound widths or out-of-sample performance) against at least one classical divergence measure to substantiate the practical utility claim.
- Notation for the state-dependent divergence function and the Musielak-Orlicz modular should be introduced once with a clear definition before being used in the optimization formulation.
Simulated Author's Rebuttal
We thank the referee for the careful reading and positive assessment of our manuscript. We are pleased that the significance of the Musielak-Orlicz framework for bounding cumulants in uncertain supOU processes is recognized, along with its relevance to applications such as streamflow modeling. No specific major comments were raised in the report.
Circularity Check
No significant circularity detected in derivation chain
full rationale
The paper introduces a framework for bounding cumulants of supOU processes under measure distortions using state-dependent divergences on Musielak-Orlicz spaces, supplies sufficient conditions for well-posedness of the resulting optimization problems, and contrasts this with the failure of Kullback-Leibler divergence. The central claims rest on standard existence arguments from Orlicz-space theory and supOU process properties rather than any reduction of the bounds to quantities defined by the same optimization, fitted parameters renamed as predictions, or load-bearing self-citations. No equation or step equates an output to its input by construction, and the derivation remains independent of the target results.
Axiom & Free-Parameter Ledger
Reference graph
Works this paper leans on
-
[1]
Beran, J., Feng, Y., Ghosh, S., Kulik, R. (2013). Long-Memory Processes. Springer, Berlin, Heidelberg
work page 2013
-
[2]
Lanoiselée, Y., Pagnini, G., & Wyłomańska, A. (2025). Super-resolved anomalous diffusion: deciphering the joint distribution of anomalous exponent and diffusion coefficient. Physical Review Letters, 135(13), 137101. https://doi.org/10.1103/y5pn-5ynd
-
[3]
Montes, R. M., & Quinones, R. A. (2025). Early detection of sea lice epidemic transitions and changes in long-term abundance levels in salmon farming areas. Aquaculture, 603, 742385. https://doi.org/10.1016/j.aquaculture.2025.742385
-
[4]
Zhao, X., & Hou, W. Intelligent parameter identification for the Black -Scholes system driven by mixed fractional Brownian motion. Chaos, Solitons & Fractals, 207, 118022. https://doi.org/10.1016/j.chaos.2026.118022
-
[5]
Laskin, N. (2024). A new approach to constructing probability distributions of fractional counting processes. Chaos, Solitons & Fractals, 186, 115268. https://doi.org/10.1016/j.chaos.2024.115268
-
[6]
Balagula, Y., Baimel, D., & Aharon, I. (2025). Comparing time series and neural network models of long memory for electricity price forecasting. Results in Engineering, 108465. https://doi.org/10.1016/j.rineng.2025.108465
-
[7]
Elnady, S. M., El-Beltagy, M., Radwan, A. G., & Fouda, M. E. (2025). A comprehensive survey of fractional gradient descent methods and their convergence analysis. Chaos, Solitons & Fractals, 194, 116154. https://doi.org/10.1016/j.chaos.2025.116154
-
[8]
Barndorff-Nielsen, O. E. (2001). Superposition of Ornstein –Uhlenbeck type processes. Theory of Probability & Its Applications, 45(2), 175 -194. https://doi.org/10.1137/S0040585X97978166
-
[9]
Barndorff-Nielsen, O. E., & Stelzer, R. (2011). Multivariate supOU processes. https://doi.org/10.1214/10 -AAP690
work page doi:10.1214/10 2011
-
[10]
Rajput, B. S., & Rosinski, J. (1989). Spectral representations of infinitely divisible processes. Probability Theory and Rela ted Fields, 82(3), 451-487. https://doi.org/10.1007/BF00339998
-
[11]
Chen, W., & Huang, S. (2025). A novel detection approach of bifurcation -induced tipping points with generalized Ornstein - Uhlenbeck process in finance. Chaos, Solitons & Fractals, 201, 117257. https://doi.org/10.1016/j.chaos.2025.117257
-
[12]
Gu, A., He, X., Chen, S., & Yao, H. (2023). Optimal investment -consumption and life insurance strategy with mispricing and model ambiguity. Methodology and Computing in Applied Probability, 25(3), 77. https://doi.org/10.1007/s11009 -023-10051- 0
-
[14]
Computer Graphics Forum 31, 2pt2 (2012), 519–528
Barndorff-Nielsen, O. E., & Stelzer, R. (2013). The multivariate supOU stochastic volatility model. Mathematical Finance: An International Journal of Mathematics, Statistics and Financial Economics, 23(2), 275 -296. https://doi.org/10.1111/j.1467- 9965.2011.00494.x
-
[15]
Yoshioka, H. (2021). Fitting a superposition of Ornstein –Uhlenbeck process to time series of discharge in a perennial river environment. The Proceedings of ANZIAM, 63, C84 -C96. https://doi.org/10.21914/anziamj.v63.16985
-
[16]
Yoshioka, H. (2025). Superposition of interacting stochastic processes with memory and its application to migrating fish counts. Chaos, Solitons & Fractals, 192, 115911. https://doi.org/10.1016/j.chaos.2024.115911
-
[17]
Kovtun, A., Leonenko, N., & Pepelyshev, A. (2025). Singular properties of high -order spectral densities of supOU processes. Communications in Nonlinear Science and Numerical Simulation, 109459. https://doi.org/10.1016/j.cnsns.2025.109459
-
[18]
Grahovac, D., & Kevei, P. (2025). Tail behavior and almost sure growth rate of superpositions of Ornstein –Uhlenbeck-type processes. Journal of theoretical probability, 38(1), 1. https://doi.org/10.1007/s10959 -024-01374-w
-
[19]
Moser, M., & Stelzer, R. (2011). Tail behavior of multivariate Lévy -driven mixed moving average processes and supOU stochastic volatility models. Advances in Applied Probability, 43(4), 1109-1135. https://doi.org/10.1239/aap/1324045701
-
[20]
Leonenko, N. N., & Pepelyshev, A. (2026). Simulation of supOU processes with specified marginal distribution and correlation function. Modern Stochastics: Theory and Applications. Published online. https://doi.org/10.15559/25-VMSTA291
-
[21]
Barndorff-Nielsen, O.E., Benth, F.E., & Veraart, A.E.D. (2018). Ambit Stochastics. Springer, Cham
work page 2018
-
[22]
Behme, A., Chong, C., & Klüppelberg, C. (2015). Superposition of COGARCH processes. Stochastic Processes and their Applications, 125(4), 1426 -1469. https://doi.org/10.1016/j.spa.2014.11.004
-
[23]
Yoshioka, H. (2026). Theoretical and computational investigations of superposed interacting affine and more complex processes. Mathematics and Computers in Simulation, 245, 628 -654. https://doi.org/10.1016/j.matcom.2026.01.013
-
[24]
Luo, H., Yang, Q., Mazloff, M., Nerger, L., & Chen, D. (2023). The impacts of optimizing model-dependent parameters on the Antarctic sea ice data assimilation. Geophysical Research Letters, 50(22), e2023GL105690. https://doi.org/10.1029/2023GL105690
-
[25]
Shao, Y., & Si, W. (2021). Degradation modeling with long-term memory considering measurement errors. IEEE Transactions on Reliability, 72(1), 177-189. https://doi.org/10.1109/TR.2021.3125958
-
[26]
Liu, N., Qian, L., Yan, D., Hu, W., & Hong, M. (2024). A nonlinear dynamical model for monthly runoff forecasting in situations of small samples. Mathematical Geosciences, 56(3), 639 -659. https://doi.org/10.1007/s11004-023-10099-1
-
[27]
Ma, C., & Yuan, N. (2025). Exploring land surface air temperature changes: a detailed trend analysis through the lens of long - term memory. Climate Dynamics, 63(8), 295. https://doi.org/10.1007/s00382-025-07791-9
-
[28]
Dyson, M., & Stemler, T. (2025). Improving forecasts of imperfect models using piecewise stochastic processes. Chaos: An Interdisciplinary Journal of Nonlinear Science, 35(2). https://doi.org/10.1063/5.0242061
-
[29]
Hansen, L. P., & Souganidis, P. (2025). Stochastic responses and marginal valuation. Proceedings of the National Academy of Sciences, 122(48), e2520857122. https://doi.org/10.1073/pnas.2520857122
-
[30]
Yoshioka, H., & Yoshioka, Y. (2024). Generalized divergences for statistical evaluation of uncertainty in long -memory processes. Chaos, Solitons & Fractals, 182, 114627. https://doi.org/10.1016/j.chaos.2024.114627
-
[31]
Yoshioka, H., Tomobe, H., & Yoshioka, Y. (2024). Orlicz risks for assessing stochastic streamflow environments: a static optimization approach. Stochastic Environmental Research and Risk Assessment, 38(1), 233 -250. https://doi.org/10.1007/s00477 -023-02561-7
-
[32]
Strati, F. (2025). Risk measures on Musielak -Orlicz spaces: A state -dependent perspective for insurance. Insurance: Mathematics and Economics, 103174. https://doi.org/10.1016/j.insmatheco.2025.103174
-
[33]
Chlebicka, I., Gwiazda, P., Åšwierczewska -Gwiazda, A., WrÃblewska-KamiÅ„ska, A. (2021). Partial Differential Equations in Anisotropic Musielak-Orlicz. Springer, Cham
work page 2021
-
[34]
Sason, I., & Verdú, S. (2016). f-divergence Inequalities. IEEE Transactions on Information Theory, 62(11), 5973 -6006. https://doi.org/10.1109/TIT.2016.2603151 42
-
[35]
Ben-Tal, A., & Teboulle, M. (2007). An old -new concept of convex risk measures: the optimized certainty equivalent. Mathematical Finance, 17(3), 449 -476. https://doi.org/10.1111/j.1467-9965.2007.00311.x
-
[36]
Fröhlich, C., & Williamson, R. C. (2023). Tailoring to the tails: Risk measures for fine -grained tail sensitivity. Transactions on Machine Learning Research. https://openreview.net/pdf?id=UntUoeLwwu
work page 2023
-
[37]
Rubshtein, BZ. A., Grabarnik, G. Y., & Muratov, M. A., Pashkova, Y.S. (2016). Foundations of Symmetric Spaces of Measurable Functions. Developments in Mathematics. Springer, Cham
work page 2016
-
[38]
Bellini, F., Laeven, R. J., & Rosazza Gianin, E. (2018). Robust return risk measures. Mathematics and Financial Economics, 12(1), 5-32. https://doi.org/10.1007/s11579-017-0188-x
-
[39]
Bellini, F., Laeven, R. J., & Gianin, E. R. (2021). Dynamic robust Orlicz premia and Haezendonck –Goovaerts risk measures. European Journal of Operational Research, 291(2), 438 -446. https://doi.org/10.1016/j.ejor.2019.08.049
-
[40]
Chudziak, J., & Rela, P. (2025a). The Orlicz premium principle under uncertainty. Revista de la Real Academia de Ciencias Exactas, Físicas y Naturales. Serie A. Matemáticas, 119(4), 116. https://doi.org/10.1007/s13398 -025-01778-1
-
[41]
Chudziak, J., & Rela, P. (2025b). On supertranslativity of the Orlicz premium principle. Aequationes mathematicae, 99(6), 2549-2563. https://doi.org/10.1007/s00010 -025-01207-z
-
[42]
Ito, K., & Kashima, K. (2024). Risk -sensitive control as inference with Rényi divergence. Advances in Neural Information Processing Systems, 37, 71381 -71413. https://proceedings.neurips.cc/paper_files/paper/2024/file/836cf992a71f7a0bda218c180f942902 -Paper-Conference.pdf
work page 2024
-
[43]
Póczos, B., & Schneider, J. (2011). On the Estimation of α-Divergences. In Proceedings of the Fourteenth International Conference on Artificial Intelligence and Statistics, pp. 609 -617. JMLR Workshop and Conference Proceedings. https://proceedings.mlr.press/v15/poczos11a/poczos11a.pdf
work page 2011
-
[44]
Boyd, S., & Vandenberghe, L. (2004). Convex optimization. Cambridge University Press
work page 2004
-
[45]
Chen, B., Chen, X., Zhang, Z., & Sun, H. (2025). Derivation and analysis of spatial variability in master recession curves wi th mixed effects model. Journal of Hydrology, 662, 133853. https://doi.org/10.1016/j.jhydrol.2025.133853
-
[46]
Gao, M., Wang, Z., Chen, X., Dong, J., & Singh, S. K. (2026). The key drivers of streamflow recession variability and their implications for robust parameterization of recession processes. Hydrological Sciences Journal. Published Online. https://doi.org/10.1080/02626667.2025.2593328
-
[47]
Zhang, R., Bu, Q., Chen, X., & Liu, J. (2025). Can storage -discharge characteristics of karst matrix system quantified through recession analysis be reliable?. Journal of Hydrology, 648, 132378. https://doi.org/10.1016/j.jhydrol.2024.132378
-
[48]
Boros, D., Borbás, E., Darougi, A., Kovács, J., & Márkus, L. (2025). A Fractional Process with Jumps for Modeling Karstic Spring Discharge Data. Mathematics, 13(18), 2928. https://doi.org/10.3390/math13182928
-
[49]
Devò, P., Basso, S., & Marani, M. (2025). Estimation of extreme floods using a statistical and conceptual model of the hydrological response. Water Resources Research, 61(5), e2024WR038667. https://doi.org/10.1029/2024WR038667
-
[50]
Houénafa, S. E., Ronoh, E. K., Johnson, O., & Moore, S. E. (2025). Lévy -induced stochastic differential equation models in rainfall–runoff systems for assessing extreme hydrological event risks. Stochastic Environmental Research and Risk Assessment, 39(4), 1537-1554. https://doi.org/10.1007/s00477-025-02931-3
-
[51]
Fasen, V., & Klüppelberg, C. (2007). Extremes of supOU processes. In Stochastic analysis and applications: The Abel Symposium 2005, pp. 339 -359. Springer, Berlin, Heidelberg. https://doi.org/10.1007/978 -3-540-70847-6_14
work page doi:10.1007/978 2007
-
[52]
Dommel, P., & Pichler, A. (2021). Convex risk measures based on divergence. Pure and Applied Functional Analysis, 6(6), 1157-1181. http://yokohamapublishers.jp/online2/oppafa/vol6/p1157.html
work page 2021
-
[53]
Grabchak, M., & Saba, S. (2025). On approximations of subordinators in Lp and the simulation of tempered stable distributions. Statistics and Computing, 35(3), 54. https://doi.org/10.1007/s11222-025-10586-x
-
[54]
Zhu, Y., & Wang, L. (2026). Dynamics of a stochastic SIS model driven by Markovian switching and Lévy jump with heavy tailed increments. Chaos, Solitons & Fractals, 202, 117552. https://doi.org/10.1016/j.chaos.2025.117552
-
[55]
Chewi, S. (2025). Lectures on Optimization. Version May 6, 2025. https://chewisinho.github.io/opt_notes_final.pdf
work page 2025
-
[56]
Diakonikolas, J., & Jordan, M. I. (2021). Generalized momentum -based methods: A Hamiltonian perspective. SIAM Journal on Optimization, 31(1), 915 -944. https://doi.org/10.1137/20M1322716
-
[57]
Xie, Z., Yin, W., & Wen, Z. (2025). ODE -Based Learning to Optimize: Z. Xie et al. Mathematical Programming. Published online. https://doi.org/10.1007/s10107 -025-02303-3
-
[58]
Yoshioka, H. (2024). Modeling stationary, periodic, and long memory processes by superposed jump -driven processes. Chaos, Solitons & Fractals, 188, 115357. https://doi.org/10.1016/j.chaos.2024.115357
-
[59]
Iwata, K., & Sugita, S. (1990). The distribution of Dezukuri in Myoudani District. Ishikawa Prefecture Hakusan Nature Conservation Center Research Report, 17, 61-64. https://www.pref.ishikawa.lg.jp/hakusan/publish/report/documents/report17 - 6.pdf (in Japanese with English Abstract)
work page 1990
-
[60]
Tanaka, T., Kobayashi, K., & Tachikawa, Y. (2021). Simultaneous flood risk analysis and its future change among all the 109 class-A river basins in Japan using a large ensemble climate simulation database d4PDF. Environmental Research Letters, 16(7), 074059. https://doi.org/10.1088/1748-9326/abfb2b
-
[61]
Chen, J., Sayama, T., Yamada, M., Tanaka, T., & Sugawara, Y. (2025). Projecting multiscale river flood changes across Japan at+ 2 C and+ 4 C climates. Earth's Future, 13(5), e2024EF005884. https://doi.org/10.1029/2024EF005884
-
[62]
Abiko, K., & Taniguchi, K. (2026). Runoff analysis in the upper Tedori River basin considering changes in rainfall and snowfall under global warming. Japanese Journal of JSCE, 82(16), 25 -16130. https://doi.org/10.2208/jscejj.25-16130 (in Japanese with English Abstract)
-
[63]
Yoshioka, H., & Yoshioka, Y. (2025). Non-Markovian superposition process model for stochastically describing concentration– discharge relationship. Chaos, Solitons & Fractals, 199, 116715. https://doi.org/10.1016/j.chaos.2025.116715
-
[64]
Calvani, G., Carbonari, C., & Solari, L. (2022). Stability analysis of submerged vegetation patterns in rivers. Water Resourc es Research, 58(8), e2021WR031901. https://doi.org/10.1029/2021WR031901
-
[65]
Latella, M., Notti, D., Baldo, M., Giordan, D., & Camporeale, C. (2024). Short -term biogeomorphology of a gravel -bed river: Integrating remote sensing with hydraulic modelling and field analysis. Earth Surface Processes and Landforms, 49(3), 1156 -
work page 2024
-
[66]
https://doi.org/10.1002/esp.5760
-
[67]
Nakamura, T., Maruyama, T., & Watanabe, S. (2001). Population Increase of the Fluvial Japanese Charr Salvelinus leucomaenis after Fishing Prohibition. Nippon Suisan Gakkaishi, 67(1), 105 -107. https://doi.org/10.2331/suisan.67.105 (in Japanese). 43
-
[68]
Huang, J., Shao, H., Gao, F., Song, J., & He, G. (2025). A data -driven prediction -decision framework for improving the resilience of hydropower systems under drought disasters. Annals of Operations Research. Published online. https://doi.org/10.1007/s10479 -025-06962-5
-
[69]
Yoshioka, H., Yoshioka, Y., & Tsujimura, M. (2025). Tractable fish growth models considering individual differences with an application to the fish Plecoglossus altivelis . Applied Mathematical Modelling, 148, 116217. https://doi.org/10.1016/j.apm.2025.116217
-
[70]
Fatoorehchi, H., & Fosbøl, P. L. (2026). On the Maximum Horizontal Distance of a Matrix’s Eigenvalues from the Imaginary Axis: A New Criterion for Control System Stability. Journal of the Franklin Institute, 108258. https://doi.org/10.1016/j.jfranklin.2025.108258
-
[71]
Walkington, N. J. (2023). Nesterov's method for convex optimization. SIAM Review, 65(2), 539 -562. https://doi.org/10.1137/21M1390037
discussion (0)
Sign in with ORCID, Apple, or X to comment. Anyone can read and Pith papers without signing in.