Latent Space Dynamics Identification for Interface Tracking with Application to Shock-Induced Pore Collapse
Pith reviewed 2026-05-19 04:42 UTC · model grok-4.3
The pith
A revised auto-encoder in latent dynamics identification tracks moving material interfaces in shock-induced pore collapse with errors below 9 percent.
A machine-rendered reading of the paper's core claim, the machinery that carries it, and where it could break.
Core claim
LaSDI-IT combines a revised auto-encoder that jointly reconstructs the physical field and a material indicator function with linear regression for latent dynamics and Gaussian process interpolation for parameter generalization. Applied to shock-induced pore collapse, this framework achieves relative prediction errors below 9 percent, accurately captures pore area and hot spot formation, matches dense training performance with half the data, and provides predictions 106 times faster than high-fidelity simulations.
What carries the argument
The revised auto-encoder architecture that jointly reconstructs the physical field and an indicator function for material regions or phases.
If this is right
- Relative prediction errors remain below 9 percent across the parameter space.
- Key quantities of interest such as pore area and hot spot formation are recovered accurately.
- The method matches the performance of dense training while using only half the data.
- Latent dynamics predictions run 106 times faster than conventional high-fidelity simulations.
- The framework extends to other systems with sharp interfaces such as multiphase flows and fracture mechanics.
Where Pith is reading between the lines
- If the joint field-plus-indicator reconstruction succeeds here, the same encoding step could support interface tracking in phase-change problems without changing the mesh.
- Gaussian process interpolation over the latent space may reduce the number of full simulations needed when exploring wider ranges of material properties.
- Data efficiency at half the samples suggests the approach could lower the upfront cost of building training sets for similar discontinuity-rich models in other fields.
Load-bearing premise
That jointly reconstructing the physical field and an indicator function for material regions will enable accurate tracking of complex interface evolution without detailed physical models or mesh adaptation.
What would settle it
A new simulation run on a different pore geometry or shock strength where the predicted interfaces and hot spots deviate from high-fidelity results by more than 9 percent relative error.
Figures
read the original abstract
Capturing sharp, evolving interfaces remains a central challenge in reduced-order modeling, especially when data is limited and the system exhibits localized nonlinearities or discontinuities. We propose LaSDI-IT (Latent Space Dynamics Identification for Interface Tracking), a data-driven framework that combines low-dimensional latent dynamics learning with explicit interface-aware encoding to enable accurate and efficient modeling of physical systems involving moving material boundaries. At the core of LaSDI-IT is a revised auto-encoder architecture that jointly reconstructs the physical field and an indicator function representing material regions or phases, allowing the model to track complex interface evolution without requiring detailed physical models or mesh adaptation. The latent dynamics are learned through linear regression in the encoded space and generalized across parameter regimes using Gaussian process interpolation with greedy sampling. We demonstrate LaSDI-IT on the problem of shock-induced pore collapse in high explosives, a process characterized by sharp temperature gradients and dynamically deforming pore geometries. The method achieves relative prediction errors below 9% across the parameter space, accurately recovers key quantities of interest such as pore area and hot spot formation, and matches the performance of dense training with only half the data. This latent dynamics prediction was 106 times faster than the conventional high-fidelity simulation, proving its utility for multi-query applications. These results highlight LaSDI-IT as a general, data-efficient framework for modeling discontinuity-rich systems in computational physics, with potential applications in multiphase flows, fracture mechanics, and phase change problems.
Editorial analysis
A structured set of objections, weighed in public.
Referee Report
Summary. The manuscript introduces LaSDI-IT, a data-driven framework for modeling physical systems with moving material interfaces. It features a revised auto-encoder that jointly reconstructs the physical field and an indicator function for material regions, learns linear latent dynamics via regression, and generalizes across parameters using Gaussian process interpolation with greedy sampling. The framework is applied to shock-induced pore collapse in high explosives, claiming relative prediction errors below 9%, accurate recovery of pore area and hot spot formation, matching dense training performance with half the data, and a 106x speedup compared to high-fidelity simulations.
Significance. If substantiated, the results demonstrate a general and data-efficient approach for reduced-order modeling of discontinuity-rich systems. The explicit handling of interfaces via the indicator function reconstruction addresses a significant challenge in latent space methods for problems involving sharp gradients and deforming geometries. The reported speedup and data efficiency would be particularly valuable for multi-query scenarios in computational physics, such as parameter studies in explosive modeling. The work builds on latent dynamics identification with an interface-aware extension.
major comments (2)
- [Abstract] Abstract: The central performance claims (relative errors below 9%, accurate recovery of pore area and hot spot formation, 106x speedup, and matching dense training with half the data) rest on an unexamined experimental setup. No details are provided on training data volume, validation splits, error bar computation, or separate quantification of indicator function reconstruction error versus field error.
- [Section 3] Section 3 (Methodology, auto-encoder description): The revised auto-encoder jointly reconstructs the physical field and indicator function to enable interface tracking without physical models or mesh adaptation. For shock-induced pore collapse with sharp temperature gradients and deforming geometries, it is unclear if the architecture or loss explicitly enforces discontinuity preservation (e.g., via level-set penalties or gradient-based terms). Standard auto-encoder smoothing could propagate into the linear latent regression and GP interpolation, directly threatening the reported accuracy and data-efficiency results.
minor comments (2)
- [Figures] Figure captions should specify the exact parameter values and time instances for the visualized snapshots to improve reproducibility and allow direct comparison with the reported errors.
- [Section 3] The notation distinguishing the latent variables for the physical field versus the indicator function component should be clarified in the equations to avoid ambiguity in the joint reconstruction loss.
Simulated Author's Rebuttal
We thank the referee for their constructive and insightful comments. We address each major comment point by point below, providing clarifications based on the manuscript content and making revisions where they strengthen the presentation without misrepresenting the work.
read point-by-point responses
-
Referee: [Abstract] Abstract: The central performance claims (relative errors below 9%, accurate recovery of pore area and hot spot formation, 106x speedup, and matching dense training with half the data) rest on an unexamined experimental setup. No details are provided on training data volume, validation splits, error bar computation, or separate quantification of indicator function reconstruction error versus field error.
Authors: We agree that the abstract would be strengthened by briefly summarizing the experimental setup to better support the performance claims. The manuscript provides these details in Sections 4 (Data Generation and Training) and 5 (Numerical Results), including the number of high-fidelity simulations used, the train/validation approach, and error metrics. To address the comment directly, we have revised the abstract to include a concise statement on the training configuration and added a dedicated paragraph in Section 5 that separately quantifies the indicator function reconstruction error relative to the physical field error. This change improves transparency while preserving the original results and claims. revision: yes
-
Referee: [Section 3] Section 3 (Methodology, auto-encoder description): The revised auto-encoder jointly reconstructs the physical field and indicator function to enable interface tracking without physical models or mesh adaptation. For shock-induced pore collapse with sharp temperature gradients and deforming geometries, it is unclear if the architecture or loss explicitly enforces discontinuity preservation (e.g., via level-set penalties or gradient-based terms). Standard auto-encoder smoothing could propagate into the linear latent regression and GP interpolation, directly threatening the reported accuracy and data-efficiency results.
Authors: The referee correctly notes that the original description leaves open the question of explicit discontinuity preservation. The joint reconstruction objective in the revised auto-encoder is designed to mitigate smoothing by requiring accurate recovery of the indicator function at material boundaries, which in turn guides the latent representation. No explicit level-set penalties or additional gradient terms were present in the loss. We have therefore revised Section 3 to include a clearer explanation of this design choice and its rationale for the present application, along with supporting analysis showing that interface sharpness is maintained sufficiently to achieve the reported accuracy. This addition addresses the concern without requiring architectural changes. revision: partial
Circularity Check
No significant circularity detected
full rationale
The LaSDI-IT framework trains a revised auto-encoder on simulation snapshots to jointly reconstruct fields and material indicator functions, then fits linear latent dynamics via regression and generalizes via Gaussian process interpolation with greedy sampling. Reported relative errors below 9% and recovery of pore area/hot spots are measured on held-out parameter instances and compared against dense training baselines, not on the same fitted quantities. No equation or claim reduces a prediction to an input by construction, no uniqueness theorem is imported from self-citation to force the architecture, and the speed-up claim is a direct timing comparison against high-fidelity simulation. The derivation chain is therefore self-contained empirical validation of a data-driven pipeline.
Axiom & Free-Parameter Ledger
Lean theorems connected to this paper
-
IndisputableMonolith/Cost/FunctionalEquation.leanwashburn_uniqueness_aczel unclear?
unclearRelation between the paper passage and the cited Recognition theorem.
revised auto-encoder architecture that jointly reconstructs the physical field and an indicator function representing material regions or phases
-
IndisputableMonolith/Foundation/RealityFromDistinction.leanreality_from_one_distinction unclear?
unclearRelation between the paper passage and the cited Recognition theorem.
latent dynamics are learned through linear regression in the encoded space and generalized across parameter regimes using Gaussian process interpolation
What do these tags mean?
- matches
- The paper's claim is directly supported by a theorem in the formal canon.
- supports
- The theorem supports part of the paper's argument, but the paper may add assumptions or extra steps.
- extends
- The paper goes beyond the formal theorem; the theorem is a base layer rather than the whole result.
- uses
- The paper appears to rely on the theorem as machinery.
- contradicts
- The paper's claim conflicts with a theorem or certificate in the canon.
- unclear
- Pith found a possible connection, but the passage is too broad, indirect, or ambiguous to say the theorem truly supports the claim.
Reference graph
Works this paper leans on
-
[1]
G. Berkooz, P. Holmes, J. L. Lumley, The proper orthogonal decomposi- tion in the analysis of turbulent flows, Annual review of fluid mechanics 25 (1) (1993) 539–575
work page 1993
-
[2]
G. Rozza, D. B. P. Huynh, A. T. Patera, Reduced basis approxima- tion and a posteriori error estimation for affinely parametrized elliptic coercive partial differential equations: application to transport and con- tinuum mechanics, Archives of Computational Methods in Engineering 15 (3) (2008) 229–275
work page 2008
-
[3]
M. G. Safonov, R. Chiang, A schur method for balanced-truncation model reduction, IEEE Transactions on automatic control 34 (7) (2002) 729–733
work page 2002
-
[4]
K. Lee, K. T. Carlberg, Model reduction of dynamical systems on non- linear manifoldsusing deepconvolutionalautoencoders, Journal ofCom- putational Physics 404 (2020) 108973
work page 2020
-
[5]
Y. Kim, Y. Choi, D. Widemann, T. Zohdi, A fast and accurate physics- informed neural network reduced order model with shallow masked au- toencoder, Journal of Computational Physics 451 (2022) 110841. 30
work page 2022
-
[6]
A. N. Diaz, Y. Choi, M. Heinkenschloss, A fast and accurate domain de- composition nonlinear manifold reduced order model, Computer Meth- ods in Applied Mechanics and Engineering 425 (2024) 116943
work page 2024
-
[7]
I. Zanardi, A. N. Diaz, S. W. Chung, M. Panesi, Y. Choi, Scalable nonlinear manifold reduced order model for dynamical systems, arXiv preprint arXiv:2412.00507 (2024)
-
[8]
D. Amsallem, M. Zahr, Y. Choi, C. Farhat, Design optimization us- ing hyper-reduced-order models, Structural and Multidisciplinary Opti- mization 51 (4) (2015) 919–940
work page 2015
-
[9]
Y. Choi, G. Boncoraglio, S. Anderson, D. Amsallem, C. Farhat, Gradient-based constrained optimization using a database of linear reduced-order models, Journal of Computational Physics 423 (2020) 109787
work page 2020
-
[10]
K. Carlberg, Y. Choi, S. Sargsyan, Conservative model reduction for finite-volume models, Journal of Computational Physics 371 (2018) 280– 314
work page 2018
-
[11]
Y. Choi, K. Carlberg, Space–time least-squares petrov–galerkin projec- tion for nonlinear model reduction, SIAM Journal on Scientific Com- puting 41 (1) (2019) A26–A58
work page 2019
-
[12]
Y. Choi, P. Brown, W. Arrighi, R. Anderson, K. Huynh, Space–time reduced order model for large-scale linear dynamical systems with ap- plication to boltzmann transport problems, Journal of Computational Physics 424 (2021) 109845
work page 2021
- [13]
- [14]
-
[15]
D. M. Copeland, S. W. Cheung, K. Huynh, Y. Choi, Reduced order models for lagrangian hydrodynamics, Computer Methods in Applied Mechanics and Engineering 388 (2022) 114259. 31
work page 2022
- [16]
-
[17]
Y. Choi, D. Coombs, R. Anderson, Sns: A solution-based nonlinear sub- space method for time-dependent model order reduction, SIAM Journal on Scientific Computing 42 (2) (2020) A1116–A1146
work page 2020
- [18]
-
[19]
Y. Kim, K. Wang, Y. Choi, Efficient space–time reduced order model for linear dynamical systems in python using less than 120 lines of code, Mathematics 9 (14) (2021) 1690
work page 2021
-
[20]
S. W. Cheung, Y. Choi, D. M. Copeland, K. Huynh, Local lagrangian reduced-order modeling for the rayleigh-taylor instability by solution manifold decomposition, Journal of Computational Physics 472 (2023) 111655
work page 2023
-
[21]
J. T. Lauzon, S. W. Cheung, Y. Shin, Y. Choi, D. M. Copeland, K. Huynh, S-opt: A points selection algorithm for hyper-reduction in reduced order models, SIAM Journal on Scientific Computing 46 (4) (2024) B474–B501
work page 2024
- [22]
-
[23]
S. W. Chung, Y. Choi, P. Roy, T. Moore, T. Roy, T. Y. Lin, D. T. Nguyen, C. Hahn, E. B. Duoss, S. E. Baker, Train small, model big: Scalable physics simulators via reduced order modeling and domain de- composition, Computer Methods in Applied Mechanics and Engineering 427 (2024) 117041
work page 2024
-
[24]
P.-H. Tsai, S. Chung, D. Ghosh, J. Loffeld, Y. Choi, J. Belof, Local reduced-order modeling for electrostatic plasmas by physics-informed solution manifold decomposition, Available at SSRN 5134633. 32
-
[25]
P. J. Schmid, Dynamic mode decomposition of numerical and experi- mental data, Journal of fluid mechanics 656 (2010) 5–28
work page 2010
-
[26]
C.W.Rowley, I.Mezić, S.Bagheri, P.Schlatter, D.S.Henningson, Spec- tral analysis of nonlinear flows, Journal of fluid mechanics 641 (2009) 115–127
work page 2009
-
[27]
thesis, Princeton University (2013)
J.H.Tu, Dynamicmodedecomposition: Theoryandapplications, Ph.D. thesis, Princeton University (2013)
work page 2013
-
[28]
J. L. Proctor, S. L. Brunton, J. N. Kutz, Dynamic mode decomposition withcontrol, SIAMJournalonAppliedDynamicalSystems15(1)(2016) 142–161
work page 2016
-
[29]
T. Kadeethum, F. Ballarin, Y. Choi, D. O’Malley, H. Yoon, N. Bouklas, Non-intrusive reduced order modeling of natural convection in porous media using convolutional autoencoders: comparison with linear sub- space techniques, Advances in Water Resources 160 (2022) 104098
work page 2022
-
[30]
A. Tran, X. He, D. A. Messenger, Y. Choi, D. M. Bortz, Weak-form latent space dynamics identification, Computer Methods in Applied Me- chanics and Engineering 427 (2024) 116998
work page 2024
-
[31]
J. S. R. Park, S. W. Cheung, Y. Choi, Y. Shin, tlasdi: Thermodynamics- informed latent space dynamics identification, Computer Methods in Applied Mechanics and Engineering 429 (2024) 117144
work page 2024
-
[32]
S. L. Brunton, J. L. Proctor, J. N. Kutz, Discovering governing equa- tions from data by sparse identification of nonlinear dynamical systems, Proceedings of the national academy of sciences 113 (15) (2016) 3932– 3937
work page 2016
-
[33]
B.Peherstorfer, K.Willcox, Data-drivenoperatorinferencefornonintru- sive projection-based model reduction, Computer Methods in Applied Mechanics and Engineering 306 (2016) 196–215
work page 2016
-
[34]
S. A. McQuarrie, C. Huang, K. E. Willcox, Data-driven reduced-order models via regularised operator inference for a single-injector combus- tion process, Journal of the Royal Society of New Zealand 51 (2) (2021) 194–211. 33
work page 2021
-
[35]
S. A. McQuarrie, P. Khodabakhshi, K. E. Willcox, Nonintrusive reduced-order models for parametric partial differential equations via data-driven operator inference, SIAM Journal on Scientific Computing 45 (4) (2023) A1917–A1946
work page 2023
-
[36]
Z. Li, N. Kovachki, K. Azizzadenesheli, B. Liu, K. Bhattacharya, A. Stu- art, A. Anandkumar, Fourier neural operator for parametric partial dif- ferential equations, arXiv preprint arXiv:2010.08895 (2020)
work page internal anchor Pith review Pith/arXiv arXiv 2010
-
[37]
N. Kovachki, Z. Li, B. Liu, K. Azizzadenesheli, K. Bhattacharya, A. Stu- art, A. Anandkumar, Neural operator: Learning maps between function spaces with applications to pdes, Journal of Machine Learning Research 24 (89) (2023) 1–97
work page 2023
-
[38]
L. Lu, P. Jin, G. E. Karniadakis, Deeponet: Learning nonlinear opera- tors for identifying differential equations based on the universal approx- imation theorem of operators, arXiv preprint arXiv:1910.03193 (2019)
work page internal anchor Pith review Pith/arXiv arXiv 1910
-
[39]
N. Rahaman, A. Baratin, D. Arpit, F. Draxler, M. Lin, F. Hamprecht, Y. Bengio, A. Courville, On the spectral bias of neural networks, in: International conference on machine learning, PMLR, 2019, pp. 5301– 5310
work page 2019
-
[40]
Y. Wang, C.-Y. Lai, Multi-stage neural networks: Function approxima- tor of machine precision, Journal of Computational Physics 504 (2024) 112865
work page 2024
-
[41]
M. Tancik, P. Srinivasan, B. Mildenhall, S. Fridovich-Keil, N. Raghavan, U. Singhal, R. Ramamoorthi, J. Barron, R. Ng, Fourier features let networks learn high frequency functions in low dimensional domains, Advances in neural information processing systems 33 (2020) 7537–7547
work page 2020
-
[42]
W. D. Fries, X. He, Y. Choi, Lasdi: Parametric latent space dynamics identification, Computer Methods in Applied Mechanics and Engineer- ing 399 (2022) 115436
work page 2022
-
[43]
X. He, Y. Choi, W. D. Fries, J. L. Belof, J.-S. Chen, glasdi: Parametric physics-informed greedy latent space dynamics identification, Journal of Computational Physics 489 (2023) 112267. 34
work page 2023
-
[44]
C. Bonneville, Y. Choi, D. Ghosh, J. L. Belof, Gplasdi: Gaussian process-based interpretable latent space dynamics identification through deep autoencoder, Computer Methods in Applied Mechanics and Engi- neering 418 (2024) 116535
work page 2024
-
[45]
F. P. Bowden, A. D. Yoffe, Initiation and growth of explosion in liquids and solids, CUP Archive, 1985
work page 1985
- [46]
-
[47]
J. E. Hicken, D. W. Zingg, Summation-by-parts operators and high- order quadrature, Journal of Computational and Applied Mathematics 237 (1) (2013) 111–125
work page 2013
-
[48]
C. E. Rasmussen, Gaussian processes in machine learning, in: Summer school on machine learning, Springer, 2003, pp. 63–71
work page 2003
-
[49]
F. Pedregosa, G. Varoquaux, A. Gramfort, V. Michel, B. Thirion, O.Grisel, M.Blondel, P.Prettenhofer, R.Weiss, V.Dubourg, J.Vander- plas, A. Passos, D. Cournapeau, M. Brucher, M. Perrot, E. Duchesnay, Scikit-learn: Machine learning in Python, Journal of Machine Learning Research 12 (2011) 2825–2830
work page 2011
-
[50]
L. E. Fried, L. Zepeda-Ruis, W. M. Howard, F. Najjar, J. E. Reaugh, The role of viscosity in tatb hot spot ignition, in: AIP Conference Pro- ceedings, Vol. 1426, American Institute of Physics, 2012, pp. 299–302
work page 2012
-
[51]
C. M. Tarver, S. K. Chidester, A. L. Nichols, Critical conditions for impact-and shock-induced hot spots in solid explosives, The Journal of Physical Chemistry 100 (14) (1996) 5794–5799
work page 1996
-
[52]
J. E. Field, Hot spot ignition mechanisms for explosives, Accounts of chemical Research 25 (11) (1992) 489–496
work page 1992
-
[53]
Menikoff, Pore collapse and hot spots in hmx, in: AIP Conference Proceedings, Vol
R. Menikoff, Pore collapse and hot spots in hmx, in: AIP Conference Proceedings, Vol. 706, American Institute of Physics, 2004, pp. 393–396. 35
work page 2004
-
[54]
V. Nesterenko, M. Bondar, I. Ershov, Instability of plastic flow at dy- namic pore collapse, in: AIP Conference Proceedings, Vol. 309, Ameri- can Institute of Physics, 1994, pp. 1173–1176
work page 1994
- [55]
- [56]
-
[57]
C. M. Miller, H. K. Springer, Probabilistic effects of porosity and chem- ical kinetics on the shock initiation of an octahydro-1, 3, 5, 7-tetranitro- 1, 3, 5, 7-tetrazocine (hmx) based explosive, Journal of Applied Physics 129 (21) (2021)
work page 2021
- [58]
-
[59]
C. R. Noble, A. T. Anderson, N. R. Barton, J. A. Bramwell, A. Capps, M. H. Chang, J. J. Chou, D. M. Dawson, E. R. Diana, T. A. Dunn, et al., Ale3d: An arbitrary lagrangian-eulerian multi-physics code, Tech. rep., Lawrence Livermore National Lab.(LLNL), Livermore, CA (United States) (2017)
work page 2017
-
[60]
P. C. H. Nguyen, Y.-T. Nguyen, P. K. Seshadri, J. B. Choi, H. Udayku- mar, S. Baek, A physics-aware deep learning model for energy local- ization in multiscale shock-to-detonation simulations of heterogeneous energetic materials, Propellants, explosives, pyrotechnics 48 (4) (2023) e202200268
work page 2023
-
[61]
C. Li, J. C. Verduzco, B. H. Lee, R. J. Appleton, A. Strachan, Mapping microstructure to shock-induced temperature fields using deep learning, npj Computational Materials 9 (1) (2023) 178
work page 2023
-
[62]
H. K. Springer, C. M. Miller, M. P. Kroonblawd, S. Bastea, Simulating the effects of grain surface morphology on hot spots in hmx with sur- rogate model development, Propellants, Explosives, Pyrotechnics 48 (4) (2023) e202200139. 36
work page 2023
-
[63]
S. W. Cheung, Y. Choi, H. K. Springer, T. Kadeethum, Data-scarce surrogate modeling of shock-induced pore collapse process, Shock Waves 34 (3) (2024) 237–256
work page 2024
-
[64]
L. E. Fried, W. M. Howard, P. C. Souers, Exp6: A new equation of state library for high pressure thermochemistry, in: 12th International Detonation Symposium, August, Citeseer, 2002, pp. 11–16
work page 2002
-
[65]
G. R. Johnson, A constitutive model and data for metals subjected to large strains, high strain rates and high temperatures, in: Proceedings of the 7th International Symposium on Ballistics, The Hague, Netherlands, 1983, 1983
work page 1983
-
[66]
H. K. Springer, S. Bastea, A. L. Nichols III, C. M. Tarver, J. E. Reaugh, Modeling the effects of shock pressure and pore morphology on hot spot mechanisms in HMX, Propellants, Explosives, Pyrotechnics 43 (8) (2018) 805–817
work page 2018
-
[67]
URLhttps://hpc.llnl.gov/hardware/compute-platforms/dane
Livermore Computing – Dane. URLhttps://hpc.llnl.gov/hardware/compute-platforms/dane
-
[68]
D. P. Kingma, J. Ba, Adam: A method for stochastic optimization, arXiv preprint arXiv:1412.6980 (2014)
work page internal anchor Pith review Pith/arXiv arXiv 2014
-
[69]
URLhttps://hpc.llnl.gov/hardware/compute-platforms/lassen 37
Livermore Computing – Lassen. URLhttps://hpc.llnl.gov/hardware/compute-platforms/lassen 37
discussion (0)
Sign in with ORCID, Apple, or X to comment. Anyone can read and Pith papers without signing in.