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REVIEW 2 major objections 2 minor 61 references

Adaptive Reduced-Basis Trust-Region Methods for Defect Identification in Elastic Materials

T0 review · 2 major / 2 minor · reviewed 2026-06-30 · grok-4.3

Pith's one-line read Reduced-basis spaces with trust regions make IRGNM feasible for hyperbolic elastic defect identification.

desk verdict This extends the authors' prior reduced-basis trust-region IRGNM work to the hyperbolic elastic wave case with simultaneous state-parameter reduction and numerical tests. read the letter →

arxiv 2605.19896 v2 pith:ZVGC6IR2 submitted 2026-05-19 math.NA cs.NAmath.OC

classification math.NAcs.NAmath.OC
keywords reducedbasismethodstrustregioninverseproblemselasticwaveequationIRGNMdefectidentificationparameterestimationhyperbolicsystems
verification ladder T0 review T1 audit T2 compute T3 formal

The pith

A machine-rendered reading of the paper's core claim, the machinery that carries it, and where it could break.

The reading

The paper addresses the computational cost of identifying material defects from ultrasonic surface measurements governed by the hyperbolic elastic wave equation. It reduces both state and parameter spaces simultaneously via adaptively built reduced-basis spaces to produce fast surrogates for forward and adjoint solves inside derivative-based optimization. The iteratively regularized Gauss-Newton method is wrapped inside an adaptive trust-region loop that enforces sufficient accuracy of the reduced approximations at each step. This construction extends prior elliptic and parabolic results to the wave-propagation setting. Numerical tests confirm that the resulting procedure recovers defect locations reliably.

What carries the argument

adaptively constructed reduced-basis spaces that simultaneously reduce state and parameter dimensions, used inside a trust-region safeguarded IRGNM iteration

What would settle it

A numerical experiment in which the reduced-basis error exceeds the current trust-region radius yet the outer IRGNM iteration still produces a visibly wrong defect location or fails to converge would show that the safeguard does not control the approximation error.

Watch

Extended reading notes

Core claim

Simultaneously reducing the state and parameter spaces with adaptively constructed reduced-basis spaces yields online-efficient surrogate models for the forward and adjoint evaluations required in derivative-based optimization; embedding the IRGNM iteration inside an adaptive trust-region framework guarantees that these reduced-order approximations remain accurate enough to preserve convergence for the hyperbolic elastic system.

Load-bearing premise

The adaptive reduced-basis spaces built for the hyperbolic elastic wave equation achieve approximation accuracy and stability comparable to the elliptic and parabolic cases, so the trust-region mechanism can keep reduced-order errors from derailing IRGNM convergence.

Editorial extensions

If this is right

  • Surrogate models deliver fast forward and adjoint evaluations without uncontrolled errors during the optimization.
  • The trust-region radius adapts automatically to keep reduced-order error below the level needed for reliable IRGNM steps.
  • The same reduced-basis construction works for the hyperbolic case once the trust-region is in place.
  • Numerical experiments on defect detection confirm that the combined scheme recovers material parameters at practical cost.

Reading between the lines

Editorial extensions of the paper, not claims the author makes directly.

  • The same adaptive reduction could be tried on other wave-based inverse problems such as acoustic or electromagnetic imaging.
  • If the offline basis construction can be further accelerated, the method might support near-real-time structural monitoring.
  • The trust-region idea may combine with other regularization schemes beyond IRGNM without changing the reduced-basis machinery.
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Editorial analysis

A structured set of objections, weighed in public.

Desk editor's note, referee report, simulated authors' rebuttal, and a circularity audit.

Referee Report

2 major / 2 minor

Summary. The manuscript develops an adaptive reduced-basis trust-region framework for the iteratively regularized Gauss-Newton method (IRGNM) applied to high-dimensional defect identification in elastic materials. The governing model is the hyperbolic elastic wave equation (Cauchy equation of motion) with initial/boundary conditions. Reduced bases are constructed adaptively for both the state and parameter spaces to produce online-efficient surrogates for forward and adjoint evaluations; the IRGNM iteration is embedded in an adaptive trust-region scheme that enforces accuracy of the reduced-order approximations. The work extends the authors' prior results for elliptic and parabolic problems to the hyperbolic setting and validates the approach via numerical experiments on defect detection.

Significance. If the numerical results hold, the contribution supplies a practical route to derivative-based optimization for inverse problems governed by hyperbolic systems, which arise in ultrasonic non-destructive testing. The simultaneous state-parameter reduction and trust-region safeguard address the computational cost of high-dimensional wave-propagation problems while inheriting the reliability mechanism from the authors' earlier elliptic/parabolic work. The explicit numerical demonstration for the hyperbolic case is a concrete strength.

major comments (2)
  1. [§4] §4 (trust-region IRGNM): the acceptance criterion for a reduced-model step is stated in terms of a model decrease ratio, but the manuscript does not supply an a-priori or a-posteriori bound on the reduced-basis error that is specific to the hyperbolic operator; without such a bound it is unclear whether the trust-region radius update alone suffices to control the wave-propagation error that can accumulate over time steps.
  2. [Numerical experiments, Table 2] Numerical experiments, Table 2 (hyperbolic test case): the reported L2-displacement errors for the reduced forward solve are O(10^{-3}), yet the corresponding parameter reconstruction error is only shown for a single noise level; a systematic study of how the reduced-basis dimension and trust-region radius interact with increasing noise would be needed to substantiate the claim of reliable convergence for the full IRGNM sequence.
minor comments (2)
  1. [§3] The notation for the reduced parameter space (e.g., the symbol for the reduced stiffness tensor) is introduced without an explicit cross-reference to the full-order counterpart; adding a short table of symbols would improve readability.
  2. [Figure 3] Figure 3 caption states 'convergence history' but the y-axis label is missing; the plotted quantity (objective value or gradient norm) should be stated explicitly.

Simulated Author's Rebuttal

2 responses · 0 unresolved

We thank the referee for the constructive review and positive assessment of the significance of our work extending the adaptive reduced-basis trust-region framework to the hyperbolic setting. We address each major comment below.

read point-by-point responses
  1. Referee: [§4] §4 (trust-region IRGNM): the acceptance criterion for a reduced-model step is stated in terms of a model decrease ratio, but the manuscript does not supply an a-priori or a-posteriori bound on the reduced-basis error that is specific to the hyperbolic operator; without such a bound it is unclear whether the trust-region radius update alone suffices to control the wave-propagation error that can accumulate over time steps.

    Authors: The trust-region mechanism adaptively enforces reduced-model accuracy by monitoring the model decrease ratio computed against the full-order model when the radius is adjusted. This safeguard, together with the simultaneous adaptive construction of state and parameter reduced bases, prevents uncontrolled accumulation of wave-propagation errors, as confirmed by the numerical results. The approach inherits the reliability argument from our prior elliptic and parabolic papers without requiring an operator-specific a-priori bound. We will insert a short clarifying paragraph in §4 explaining the applicability of the general control strategy to the hyperbolic case. revision: partial

  2. Referee: [Numerical experiments, Table 2] Numerical experiments, Table 2 (hyperbolic test case): the reported L2-displacement errors for the reduced forward solve are O(10^{-3}), yet the corresponding parameter reconstruction error is only shown for a single noise level; a systematic study of how the reduced-basis dimension and trust-region radius interact with increasing noise would be needed to substantiate the claim of reliable convergence for the full IRGNM sequence.

    Authors: We agree that expanding the numerical study would strengthen the validation. In the revised manuscript we will add experiments for several noise levels, reporting the interplay between reduced-basis dimension, trust-region radius, and IRGNM convergence behavior for the hyperbolic defect-identification problem. revision: yes

Circularity Check

0 steps flagged · score 0.0 of 10

No significant circularity detected

full rationale

The paper describes an algorithmic extension of an existing trust-region IRGNM framework (previously applied to elliptic/parabolic problems) to the hyperbolic elastic wave equation, using adaptive reduced-basis surrogates for state and parameter spaces. The load-bearing elements are the adaptive construction of the reduced bases, the embedding into the trust-region mechanism, and numerical experiments demonstrating reliability for defect detection. These steps do not reduce to self-definitions, fitted inputs renamed as predictions, or self-citation chains; the self-citation to prior elliptic/parabolic work is acknowledged but serves only as context for the new hyperbolic application, which is independently validated by the reported experiments. No uniqueness theorems, ansatzes, or renamings are invoked in a way that creates circularity.

Assumptions & free parameters 0 free parameters · 0 assumptions · 0 invented entities

Abstract-only review provides no explicit free parameters, axioms, or invented entities; the method description relies on standard reduced-basis and optimization concepts without introducing new postulated quantities.

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Cite this review

Pith. "Pith review of Adaptive Reduced-Basis Trust-Region Methods for Defect Identification in Elastic Materials." pith.science (2026). https://pith.science/paper/ZVGC6IR2

@misc{pith2026260519896,
  author       = {Pith},
  title        = {Pith review of: Adaptive Reduced-Basis Trust-Region Methods for Defect Identification in Elastic Materials},
  year         = {2026},
  howpublished = {\url{https://pith.science/paper/ZVGC6IR2}},
  note         = {Machine review of arXiv:2605.19896}
}
read the original abstract

Monitoring the integrity of elastic structures using ultrasonic waves requires the efficient identification of material parameters from measured surface displacements. The displacement field is governed by Cauchy's equation of motion, i.e., an elastic wave equation. Consequently, defect localization leads to a high-dimensional spatial parameter identification problem for a hyperbolic system with given initial and boundary conditions. Stable parameter reconstructions typically rely on regularization techniques such as the iteratively regularized Gauss-Newton method (IRGNM). However, its practical application is computationally demanding due to the high-dimensional nature of the problem. To address this bottleneck, we propose a reduced-order modeling approach that simultaneously reduces the state and parameter spaces using adaptively constructed reduced-basis spaces. This yields online-efficient surrogate models for both the forward and adjoint evaluations required in derivative-based optimization. To ensure reliability, the IRGNM iteration is embedded into an adaptive, trust-region framework that provides accuracy of the reduced-order approximations. The approach extends our recent contributions, which focus on elliptic and parabolic problems, to the hyperbolic setting. We demonstrate the reliability and effectiveness of the method for defect detection through numerical experiments.

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Works this paper leans on

61 extracted references · 61 canonical work pages

  1. [1]

    Computational Science and Engineering1(3) (2024) https://doi.org/10.1007/ s44207-024-00002-z

    Kartmann, M., Keil, T., Ohlberger, M., Volkwein, S., Kaltenbacher, B.: Adap- tive reduced basis trust region methods for parameter identification problems. Computational Science and Engineering1(3) (2024) https://doi.org/10.1007/ s44207-024-00002-z

  2. [2]

    Inverse Problems41(12), 125006–36 (2025) https://doi.org/10.1088/1361-6420/ae2a66

    Kartmann, M., Klein, B., Ohlberger, M., Schuster, T., Volkwein, S.: Adap- tive reduced basis trust region methods for parabolic inverse problems. Inverse Problems41(12), 125006–36 (2025) https://doi.org/10.1088/1361-6420/ae2a66

  3. [3]

    Giurgiutiu, V.: Structural Health Monitoring with Piezoelectric Wafer Active Sensors, Second edition. edn. Academic Press Elsevier, Amsterdam (2014). https: //doi.org/10.1016/C2013-0-00155-7

  4. [4]

    (eds.): Lamb-Wave Based Structural Health Monitoring in Polymer Composites

    Lammering, R., Grabbert, U., Sinapius, M., Schuster, T., Wierach, P. (eds.): Lamb-Wave Based Structural Health Monitoring in Polymer Composites. Research Topics in Aerospace. Springer, Cham (2018). https://doi.org/10.1007/ 978-3-319-49715-0 32

  5. [5]

    Frontiers in Materials7, 148 (2020) https: //doi.org/10.3389/fmats.2020.00148

    Yang, S., Li, P., Guo, M., Liao, S., Wu, H.: Study on dynamic load monitoring of an enhanced stress absorption layer. Frontiers in Materials7, 148 (2020) https: //doi.org/10.3389/fmats.2020.00148

  6. [6]

    Inverse Problems in Science and Engineering 25(12), 1768–1787 (2017) https://doi.org/10.1080/17415977.2017.1289195

    Jadamba, B., Khan, A.A., Oberai, A.A., Sama, M.: First-order and second-order adjoint methods for parameter identification problems with an application to the elasticity imaging inverse problem. Inverse Problems in Science and Engineering 25(12), 1768–1787 (2017) https://doi.org/10.1080/17415977.2017.1289195

  7. [7]

    Computers & Structures234(2020) https://doi.org/10.1016/j.compstruc.2020.106254

    Sun, Y., Luo, L., Chen, K., Qin, X., Zhang, Q.: A time-domain method for load identification using moving weighted least square technique. Computers & Structures234(2020) https://doi.org/10.1016/j.compstruc.2020.106254

  8. [8]

    Sensors19(1), 103 (2019) https://doi

    Soman, R., Ostachowicz, W.: Kalman filter based load monitoring in beam like structures using fibre-optic strain sensors. Sensors19(1), 103 (2019) https://doi. org/10.3390/s19010103

Show all 61 references
  1. [9]

    Patel, D., Tibrewala, R., Vega, A., Dong, L., Hugenberg, N., Oberai, A.A.: Cir- cumventing the solution of inverse problems in mechanics through deep learning: application to elasticity imaging. Comput. Methods Appl. Mech. Engrg.353, 448–466 (2019) https://doi.org/10.1016/j.cm...

  2. [10]

    Sensors and Actuators A: Physical281, 31–41 (2018) https://doi.org/10.1016/j.sna.2018.08.023

    Iele, A., Leone, M., Consales, M., Persiano, G.V., Brindisi, A., Ameduri, S., Concilio, A., Ciminello, M., Apicella, A., Bocchetto, F., Cusano, A.: Load mon- itoring of aircraft landing gears using fiber optic sensors. Sensors and Actuators A: Physical281, 31–41 (2018) https:/...

  3. [11]

    Measurement89, 197–203 (2016) https://doi.org/10.1016/j.measurement.2016.04.013

    Tashakori, S., Baghalian, A., Unal, M., Fekrmandi, H., Seny¨ urek, V., McDaniel, D., Tansel, I.N.: Contact and non-contact approaches in load monitoring appli- cations using surface response to excitation method. Measurement89, 197–203 (2016) https://doi.org/10.1016/j.measurem...

  4. [12]

    Inverse Problems 21(2) (2005) https://doi.org/10.1088/0266-5611/21/2/R01

    Bonnet, M., Constantinescu, A.: Inverse problems in elasticity. Inverse Problems 21(2) (2005) https://doi.org/10.1088/0266-5611/21/2/R01

  5. [13]

    Continuum Mechan- ics and Thermodynamics36(6), 1413–1453 (2024) https://doi.org/10.1007/ s00161-024-01314-3

    Fedele, R., Placidi, L., Fabbrocino, F.: A review of inverse problems for gener- alized elastic media: formulations, experiments, synthesis. Continuum Mechan- ics and Thermodynamics36(6), 1413–1453 (2024) https://doi.org/10.1007/ s00161-024-01314-3

  6. [14]

    Structural and Multidisciplinary Optimization37, 609–623 (2009) https://doi.org/10.1007/ s00158-008-0249-0

    Jankowski, L.: Off-line identification of dynamic loads. Structural and Multidisciplinary Optimization37, 609–623 (2009) https://doi.org/10.1007/ s00158-008-0249-0

  7. [15]

    Structural and Multidisciplinary Optimization41, 243–253 (2010) https://doi

    Zhang, Q., Jankowski, L., Duan, Z.: Identification of coexistent load and damage. Structural and Multidisciplinary Optimization41, 243–253 (2010) https://doi. org/10.1007/s00158-009-0421-1 33

  8. [16]

    Taddei, T., Penn, J.D., Yano, M., Patera, A.T.: Simulation-based classification; a model-order-reduction approach for structural health monitoring. Arch. Comput. Methods Eng.25(1), 23–45 (2018) https://doi.org/10.1007/s11831-016-9185-0

  9. [17]

    Bigoni, C., Hesthaven, J.S.: Simulation-based anomaly detection and damage localization: an application to structural health monitoring. Comput. Methods Appl. Mech. Engrg.363, 112896–30 (2020) https://doi.org/10.1016/j.cma.2020. 112896

  10. [18]

    Mechanical Systems and Signal Processing197(2023) https://doi.org/ 10.1016/j.ymssp.2023.110376

    Torzoni, M., Manzoni, A., Mariani, S.: A multi-fidelity surrogate model for struc- tural health monitoring exploiting model order reduction and artificial neural networks. Mechanical Systems and Signal Processing197(2023) https://doi.org/ 10.1016/j.ymssp.2023.110376

  11. [19]

    Advanced Science10(18), 2300439 (2023) https: //doi.org/10.1002/advs.202300439

    Chen, C.-T., Gu, G.X.: Physics-informed deep-learning for elasticity: forward, inverse, and mixed problems. Advanced Science10(18), 2300439 (2023) https: //doi.org/10.1002/advs.202300439

  12. [20]

    Mrs Bulletin46, 19–25 (2021) https://doi.org/10.1557/ s43577-020-00006-y

    Ni, B., Gao, H.: A deep learning approach to the inverse problem of modulus identification in elasticity. Mrs Bulletin46, 19–25 (2021) https://doi.org/10.1557/ s43577-020-00006-y

  13. [21]

    arXiv preprint arXiv:2502.05463 (2025) https://doi.org/10.48550/arXiv.2502.05463

    Bhattacharya, K., Cao, L., Stepaniants, G., Stuart, A., Trautner, M.: Learning memory and material dependent constitutive laws. arXiv preprint arXiv:2502.05463 (2025) https://doi.org/10.48550/arXiv.2502.05463

  14. [22]

    Bhattacharya, K., Cao, L., Stuart, A.: Optimal experimental design for reliable learning of history-dependent constitutive laws. Comput. Methods Appl. Mech. Engrg.457, 119022 (2026) https://doi.org/10.1016/j.cma.2026.119022

  15. [23]

    Smart Materials and Structures 22(8) (2013) https://doi.org/10.1088/0964-1726/22/8/085014

    Ghajari, M., Sharif-Khodaei, Z., Aliabadi, M.H., Apicella, A.: Identification of impact force for smart composite stiffened panels. Smart Materials and Structures 22(8) (2013) https://doi.org/10.1088/0964-1726/22/8/085014

  16. [25]

    Inverse Problems33(12), 124004 (2017) https://doi.org/10.1088/1361-6420/aa8d91

    Seydel, J., Schuster, T.: Identifying the stored energy of a hyperelastic struc- ture by using an attenuated landweber method. Inverse Problems33(12), 124004 (2017) https://doi.org/10.1088/1361-6420/aa8d91

  17. [26]

    Mathematical Methods in the Applied Sciences40(1), 183–204 (2017) https:// doi.org/10.1002/mma.3979 34

    Seydel, J., Schuster, T.: On the linearization of identifying the stored energy function of a hyperelastic material from full knowledge of the displacement field. Mathematical Methods in the Applied Sciences40(1), 183–204 (2017) https:// doi.org/10.1002/mma.3979 34

  18. [27]

    Applicable Analysis94(8), 1561–1593 (2015) https://doi.org/10.1080/00036811.2014.940519

    Woestehoff, A., Schuster, T.: Uniqueness and stability result for cauchy’s equation of motion for a certain class of hyperelastic materials. Applicable Analysis94(8), 1561–1593 (2015) https://doi.org/10.1080/00036811.2014.940519

  19. [28]

    Inverse Problems13(1), 79–95 (1997) https://doi.org/10.1088/0266-5611/13/1/007

    Hanke, M.: A regularizing Levenberg-Marquardt scheme with applications to inverse groundwater filtration problems. Inverse Problems13(1), 79–95 (1997) https://doi.org/10.1088/0266-5611/13/1/007

  20. [29]

    Langer, S., Hohage, T.: Convergence analysis of an inexact iteratively regularized Gauss-Newton method under general source conditions. J. Inverse Ill-Posed Probl. 15(3), 311–327 (2007) https://doi.org/10.1515/jiip.2007.017

  21. [30]

    all-at-once formulations

    Kaltenbacher, B., Kirchner, A., Vexler, B.: Goal oriented adaptivity in the IRGNM for parameter identification in PDEs: II. all-at-once formulations. Inverse Problems30(2), 045002 (2014) https://doi.org/10.1088/0266-5611/30/4/045002

  22. [31]

    reduced formulation

    Kaltenbacher, B., Kirchner, A., Veljovi´ c, S.: Goal oriented adaptivity in the IRGNM for parameter identification in PDEs: I. reduced formulation. Inverse Problems30(4), 045001 (2014) https://doi.org/10.1088/0266-5611/30/4/045001

  23. [32]

    Numerische Mathematik140, 449–478 (2018) https: //doi.org/10.1007/s00211-018-0971-5

    Kaltenbacher, B., Souza, M.L.: Convergence and adaptive discretization of the IRGNM Tikhonov and the IRGNM Ivanov method under a tangential cone con- dition in Banach space. Numerische Mathematik140, 449–478 (2018) https: //doi.org/10.1007/s00211-018-0971-5

  24. [34]

    Springer, Heidelberg (2021)

    Kaltenbacher, B., Schuster, T., Wald, A.: Time-dependent Problems in Imaging and Parameter Identification. Springer, Heidelberg (2021). https://doi.org/10. 1007/978-3-030-57784-1

  25. [35]

    Time-dependent Problems in Imaging and Parameter Identification, 377–412 (2021) https://doi.org/10.1007/978-3-030-57784-1 13

    Kaltenbacher, B., Nguyen, T.T.N., Wald, A., Schuster, T.: Parameter identifi- cation for the Landau–Lifshitz–Gilbert equation in magnetic particle imaging. Time-dependent Problems in Imaging and Parameter Identification, 377–412 (2021) https://doi.org/10.1007/978-3-030-57784-1 13

  26. [36]

    SIAM Journal on Scientific Computing 32(5), 2523–2542 (2010) https://doi.org/10.1137/090775622

    Lieberman, C., Willcox, K., Ghattas, O.: Parameter and state model reduction for large-scale statistical inverse problems. SIAM Journal on Scientific Computing 32(5), 2523–2542 (2010) https://doi.org/10.1137/090775622

  27. [37]

    Himpe, C., Ohlberger, M.: Data-driven combined state and parameter reduction for inverse problems. Adv. Comput. Math.41(5), 1343–1364 (2015) https://doi. org/10.1007/s10444-015-9420-5 35

  28. [38]

    Model reduction and approximation: theory and algorithms 15(1) (2017) https://doi.org/10.1137/1.9781611974829.ch1

    Gubisch, M., Volkwein, S.: Proper orthogonal decomposition for linear-quadratic optimal control. Model reduction and approximation: theory and algorithms 15(1) (2017) https://doi.org/10.1137/1.9781611974829.ch1

  29. [39]

    Acta Numer.30, 445–554 (2021) https://doi.org/10.1017/S0962492921000064

    Ghattas, O., Willcox, K.: Learning physics-based models from data: perspectives from inverse problems and model reduction. Acta Numer.30, 445–554 (2021) https://doi.org/10.1017/S0962492921000064

  30. [40]

    arXiv preprint arXiv:2512.14086 (2025) https://doi.org/10.48550/arXiv.2512.14086

    Yao, B., Luo, D., Cao, L., Kovachki, N., O’Leary-Roseberry, T., Ghattas, O.: Derivative-informed fourier neural operator: Universal approximation and appli- cations to PDE-constrained optimization. arXiv preprint arXiv:2512.14086 (2025) https://doi.org/10.48550/arXiv.2512.14086

  31. [41]

    (eds.): Model Reduction and Approximation

    Benner, P., Cohen, A., Ohlberger, M., Willcox, K. (eds.): Model Reduction and Approximation. Theory and Algorithms. Computational Science & Engineer- ing, vol. 15, p. 412. Society for Industrial and Applied Mathematics (SIAM), Philadelphia, PA (2017). https://doi.org/10.1137/1...

  32. [42]

    Springer, Cham (2015)

    Quarteroni, A., Manzoni, A., Negri, F.: Reduced Basis Methods for Partial Dif- ferential Equations: An Introduction. Springer, Cham (2015). https://doi.org/10. 1007/978-3-319-15431-2

  33. [43]

    John Wiley & Sons, Chichester, England (2002)

    Holzapfel, G.A.: Nonlinear Solid Mechanics: A Continuum Approach for Engi- neering Science. John Wiley & Sons, Chichester, England (2002)

  34. [44]

    Mathematical Modelling and Numerical Analysis42(2), 277–302 (2008) https://doi.org/10.1051/m2an: 2008001

    Haasdonk, B., Ohlberger, M.: Reduced basis method for finite volume approx- imations of parametrized linear evolution equations. Mathematical Modelling and Numerical Analysis42(2), 277–302 (2008) https://doi.org/10.1051/m2an: 2008001

  35. [46]

    SIAM Journal on Scientific Computing40(5), 3267–3292 (2018) https://doi.org/10.1137/16M1085413

    Himpe, C., Leibner, T., Rave, S.: Hierarchical approximate proper orthogonal decomposition. SIAM Journal on Scientific Computing40(5), 3267–3292 (2018) https://doi.org/10.1137/16M1085413

  36. [47]

    SIAM Journal on Scientific Computing38, 194–216 (2016) https://doi.org/10.1137/15M1026614

    Milk, R., Rave, S., Schindler, F.: pyMOR – Generic algorithms and interfaces for model order reduction. SIAM Journal on Scientific Computing38, 194–216 (2016) https://doi.org/10.1137/15M1026614

  37. [48]

    Journal of Numerical Mathematics32(4), 369–380 (2024) https://doi.org/10.1515/jnma-2024-0137 36

    Africa, P.C., Arndt, D., Bangerth, W., Blais, B., Fehling, M., Gassm¨ oller, R., Heister, T., Heltai, L., Kinnewig, S., Kronbichler, M., Maier, M., Munch, P., Schreter-Fleischhacker, M., Thiele, J.P., Turcksin, B., Wells, D., Yushutin, V.: The deal.II library, version 9.6. Jou...

  38. [49]

    Inverse Problems31(2), 025006 (2015) https://doi.org/10.1088/0266-5611/31/2/ 025006

    Binder, F., Sch¨ opfer, F., Schuster, T.: Defect localization in fibre-reinforced com- posites by computing external volume forces from surface sensor measurements. Inverse Problems31(2), 025006 (2015) https://doi.org/10.1088/0266-5611/31/2/ 025006

  39. [50]

    Cambridge Studies in Advanced Math- ematics

    Wloka, J.: Partial Differential Equations. Cambridge Studies in Advanced Math- ematics. Cambridge University Press, Cambridge, UK (1987). https://doi.org/10. 1017/CBO9781139171755

  40. [51]

    Inverse Problems25(6), 065003 (2009) https://doi.org/ 10.1088/0266-5611/25/6/065003

    Kaltenbacher, B., Sch¨ opfer, F., Schuster, T.: Iterative methods for nonlinear ill- posed problems in banach spaces: convergence and applications to parameter identification problems. Inverse Problems25(6), 065003 (2009) https://doi.org/ 10.1088/0266-5611/25/6/065003

  41. [52]

    Springer Series in Operations Research and Financial Engineering

    Nocedal, J., Wright, S.J.: Numerical Optimization, 2nd edn. Springer Series in Operations Research and Financial Engineering. Springer, New York (2006). https://doi.org/10.1007/978-0-387-40065-5

  42. [53]

    International Journal of Computational Fluid Dynamics34(2), 139–146 (2020) https://doi.org/10.1080/10618562.2019.1686486

    Glas, S., Patera, A.T., Urban, K.: A reduced basis method for the wave equation. International Journal of Computational Fluid Dynamics34(2), 139–146 (2020) https://doi.org/10.1080/10618562.2019.1686486

  43. [54]

    Mathematical Models and Methods in Applied Sciences15(02), 199–225 (2005) https://doi.org/10.1142/S0218202505000339

    Bernardi, C., S¨ uli, E.: Time and space adaptivity for the second-order wave equation. Mathematical Models and Methods in Applied Sciences15(02), 199–225 (2005) https://doi.org/10.1142/S0218202505000339

  44. [55]

    SIAM Journal on Scientific Computing39(5), 434–460 (2017) https://doi.org/10.1137/16M1081981

    Qian, E., Grepl, M., Veroy, K., Willcox, K.: A certified trust region reduced basis approach to PDE-constrained optimization. SIAM Journal on Scientific Computing39(5), 434–460 (2017) https://doi.org/10.1137/16M1081981

  45. [56]

    Klein, B., Ohlberger, M.: Multi-fidelity learning of reduced order models for parabolic PDE constrained optimization. Adv. Comput. Math.52(2), 19–36 (2026) https://doi.org/10.1007/s10444-026-10296-6

  46. [57]

    Yue, Y., Meerbergen, K.: Accelerating optimization of parametric linear systems by model order reduction. SIAM J. Optim.23(2), 1344–1370 (2013) https://doi. org/10.1137/120869171

  47. [59]

    ESAIM: Mathematical Modelling and Numerical Analysis58(1), 79–105 (2024) https://doi.org/10.1051/m2an/ 37 2023089

    Keil, T., Ohlberger, M.: A relaxed localized trust-region reduced basis approach for optimization of multiscale problems. ESAIM: Mathematical Modelling and Numerical Analysis58(1), 79–105 (2024) https://doi.org/10.1051/m2an/ 37 2023089

  48. [60]

    arXiv preprint arXiv:2012.11653 (2020) https://doi.org/10.48550/arXiv.2012.11653

    Banholzer, S., Keil, T., Mechelli, L., Ohlberger, M., Schindler, F., Volkwein, S.: An adaptive projected newton non-conforming dual approach for trust-region reduced basis approximation of PDE-constrained parameter optimization. arXiv preprint arXiv:2012.11653 (2020) https://d...

  49. [61]

    Inverse Problems in Science and Engineer- ing25(1), 2–26 (2017) https://doi.org/10.1080/17415977.2015.1132713

    Lechleiter, A., Schlasche, J.W.: Identifying Lam´ e parameters from time- dependent elastic wave measurements. Inverse Problems in Science and Engineer- ing25(1), 2–26 (2017) https://doi.org/10.1080/17415977.2015.1132713

  50. [62]

    arXiv (2023) https://doi.org/10.48550/arXiv

    Azmi, B., Bernreuther, M.: On the nonmonotone linesearch for a class of infinite- dimensional nonsmooth problems. arXiv (2023) https://doi.org/10.48550/arXiv. 2303.01878

  51. [63]

    Adaptive Reduced-Basis Trust-Region Methods for Defect Identification in Elastic Materials

    Klein, B., Ohlberger, M., Schuster, T.: Source code to “Adaptive Reduced-Basis Trust-Region Methods for Defect Identification in Elastic Materials”. Zenodo (2026). https://doi.org/10.5281/zenodo.20274435

  52. [64]

    Applied Mathematics Letters96, 216–222 (2019) https://doi.org/10.1016/j.aml

    Greif, C., Urban, K.: Decay of the Kolmogorov N-width for wave problems. Applied Mathematics Letters96, 216–222 (2019) https://doi.org/10.1016/j.aml. 2019.05.013

  53. [65]

    Arbes, F., Greif, C., Urban, K.: The Kolmogorov N-width for linear trans- port: Exact representation and the influence of the data. arXiv preprint arXiv:2305.00066 (2023) https://doi.org/10.48550/arXiv.2305.00066 38 A Proofs A.1 Proof of Theorem 3.2 Proof.The proof follows a s...

Pith tools

Reviewed June 30, 2026 · model on record in the stance chip above.