pith. sign in

arxiv: 2406.01857 · v5 · submitted 2024-06-04 · 💻 cs.LG · cs.NA· math.NA

Neural Green's Operators for Parametric Partial Differential Equations

Pith reviewed 2026-05-24 00:23 UTC · model grok-4.3

classification 💻 cs.LG cs.NAmath.NA
keywords neural operatorsGreen's functionsparametric PDEsoperator learningdeep learninggeneralizationpreconditionersPDE solvers
0
0 comments X

The pith

Neural Green's Operators learn the coefficient dependence of Green's functions while exactly preserving their linear action on source terms.

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

The paper presents Neural Green's Operators as a way to build parametric neural operators for PDEs by starting from finite-dimensional Green's operator representations. Instead of learning the full solution map and all its parameter dependencies at once, the construction uses neural networks only to approximate how the Green's function varies with PDE coefficients. The linear mapping from inhomogeneities to solutions remains exact by design in the finite representation. This setup allows natural inclusion of properties like symmetry and conservation laws. Tests on standard PDEs show the approach matches or exceeds the accuracy of other neural operator methods with comparable size while generalizing much better outside the training data distribution.

Core claim

The central construction defines Neural Green's Operators by approximating the nonlinear dependence of the Green's function on PDE coefficients via neural networks, while the linear action of the Green's operator on inhomogeneity fields is preserved exactly within the finite-dimensional representation. This reduces the learning problem from the full solution operator to only the Green's function and its coefficient dependence. The explicit form permits embedding of symmetry, spectral, and conservation properties into the architecture. Benchmarks demonstrate comparable or superior accuracy to Deep Operator Networks, Variationally Mimetic Operator Networks, and Fourier Neural Operators at same

What carries the argument

Finite-dimensional Green's operator representations in which neural networks approximate only the nonlinear coefficient dependence of the Green's function.

If this is right

  • Comparable or better accuracy than DeepONet, VMON, and FNO with similar parameter counts on canonical PDEs.
  • Significantly better generalization when tested on out-of-distribution data.
  • Single time-step training produces pointwise-accurate dynamics in autoregressive manner over arbitrarily large numbers of time steps for time-dependent parametric PDEs.
  • Training exclusively on linear problem solutions allows accurate solutions for nonlinear PDEs when embedded in iterative solvers with suitable initial guess.
  • Explicit Green's function representations enable construction of effective matrix preconditioners that accelerate iterative PDE solvers.

Where Pith is reading between the lines

These are editorial extensions of the paper, not claims the author makes directly.

  • Separating the linear and nonlinear parts in this way may make it easier to incorporate physical constraints or hybrid numerical-neural schemes.
  • The preconditioner application suggests NGOs could speed up traditional solvers even without full replacement.
  • Improved OOD performance might be due to the lower complexity of learning only the Green's function map.
  • Extension to more complex geometries or higher dimensions would test whether the finite-representation assumption scales.

Load-bearing premise

The nonlinear dependence of the Green's function on PDE coefficients can be approximated by neural networks in a way that keeps the exact linear action on inhomogeneity fields for the finite-dimensional representations used.

What would settle it

Run an NGO on a fixed set of coefficients and check whether solutions for linear combinations of source terms exactly match the linear combination of individual solutions, or measure accuracy collapse on coefficients outside the training distribution range.

Figures

Figures reproduced from arXiv: 2406.01857 by Hugo Melchers, Joost Prins, Michael Abdelmalik.

Figure 1
Figure 1. Figure 1: Architecture of the neural Green’s operator (NGO), that maps the material parameter θ(x), forcing f(x) and boundary conditions gi(x) onto the solution u(x). For a model-NGO, F is given by (3.2), whereas for a data-NGO, F is given by (3.5). The system￾network, shown in blue, is the only machine learning based component in the NGO. 3.1.2 Data-free NGO The data-free NGO can be used in the case where the targe… view at source ↗
Figure 2
Figure 2. Figure 2: The use cases and characteristics of the model NGO, data-free NGO and data NGO. data is available (for example, when dealing with experimental data). The input to the system net of a data NGO is given by Fn[θ] = Z Ω ψnθdx ′ , (3.5) and it is trained on the solution loss as given by Equation 3.3. Just like for a model NGO, the data NGO error lower bound in the norm of 3.3 is given by ∥u p − u∥. The use case… view at source ↗
Figure 3
Figure 3. Figure 3: Left: the exact Green’s function for the 1D advection-diffusion equation [PITH_FULL_IMAGE:figures/full_fig_p009_3.png] view at source ↗
Figure 4
Figure 4. Figure 4: An overview of the filtering process as done in CNOs. [PITH_FULL_IMAGE:figures/full_fig_p010_4.png] view at source ↗
Figure 5
Figure 5. Figure 5: An overview of the interpolation process as done in CNOs. [PITH_FULL_IMAGE:figures/full_fig_p011_5.png] view at source ↗
Figure 6
Figure 6. Figure 6: Left: a single Dirichlet kernel basis function. Right: a full function basis, [PITH_FULL_IMAGE:figures/full_fig_p012_6.png] view at source ↗
Figure 7
Figure 7. Figure 7: Relative test L2 error of model NGOs with and without embedded scale equivariance, versus the (a) offset bθ and (b) amplitude cθ of the material parameter θ(x) = bθ + cθGRFλθ (x). The scale equivariance makes the NGO more robust against scale variations in the material parameter θ(x). Points and error bars are, respectively, averages and 95% confidence intervals on 1000 steady diffusion manufactured soluti… view at source ↗
Figure 8
Figure 8. Figure 8: (a) Relative L2 test error versus the order K of the truncated Neumann series of a FEM that uses an approximate matrix inversion using a Neumann series, and a Neumann model NGO as defined in Equation (3.19)). The model NGO effectively learns about two additional terms of the Neumann series, and converges to the projection error at K ≈ 5. (b) The relative L2 test error versus the spectral radius of −δFF−1 0… view at source ↗
Figure 9
Figure 9. Figure 9: The unit square domain Ω, with Neumann boundaries ΓN on the top and bottom, and Dirichlet boundaries ΓD on the left and right. expressed in terms of the Green’s function as u(x) = Z Ω G[θ](x, x ′ )f(x ′ )dx ′ + Z ΓN G[θ](x, x ′ )η(x ′ )dx ′ − Z ΓD gˆn · ∇x′G[θ](x, x ′ )dx ′ . (4.2) All neural operators were trained to learn the solution operator (θ, f, η, g) 7→ u. The way the training data is generated is … view at source ↗
Figure 10
Figure 10. Figure 10: Five random samples of solutions from both the finite element data set [PITH_FULL_IMAGE:figures/full_fig_p017_10.png] view at source ↗
Figure 11
Figure 11. Figure 11: Error box plots of the different models on the heat equation problem. [PITH_FULL_IMAGE:figures/full_fig_p018_11.png] view at source ↗
Figure 12
Figure 12. Figure 12: True solution and relative solution error of four different models, tested on [PITH_FULL_IMAGE:figures/full_fig_p019_12.png] view at source ↗
Figure 13
Figure 13. Figure 13: True solution and predicted solutions of four different models, tested on [PITH_FULL_IMAGE:figures/full_fig_p020_13.png] view at source ↗
Figure 14
Figure 14. Figure 14: Relative L2 test error versus test data length scale for a bare NN (here a U￾Net), and the same NN, when used in a DeepONet, VarMiON, data NGO, data-free NGO and model NGO. Only the NGOs manage to keep the errors small inside and in particular outside of the training data distribution. This is a result of the NGOs’ embedded Green’s operator structure, and their more favorable scaling of model size with qu… view at source ↗
Figure 15
Figure 15. Figure 15: The relation between the input function quadrature points xq and the NN input for bare NNs, DeepONets, VarMiONs, data NGOs and model NGOs. In contrast to NNs, DeepONets and VarMiONs, the input vector size (and thereby often the model size) is independent of the quadrature density Q, which makes them more scalable to multiscale problems where finer quadrature is required. In [PITH_FULL_IMAGE:figures/full_… view at source ↗
Figure 16
Figure 16. Figure 16: (a) Comparison of the error of a few canonical NN architectures when used naively in isolation, versus the same NN when used as system net in a 10x10 cubic B-spline model NGO. Whereas the FNO is most accurate of the bare NNs, the U-Net performs best when used as system net in this particular B-spline model NGO. (b) Comparison of the L2 projection errors of solutions projected on a few canonical bases havi… view at source ↗
Figure 17
Figure 17. Figure 17: The relative L2 test error of a data NGO, data-free NGO, model NGO, in comparison to FEM and projection errors, versus the (a) number of assembly quadrature points per dimension Q1/d, (b) number of loss quadrature points per dimension Q 1/d L , (c) number of basis functions N, (d) number of trainable parameters Nw, (e) number of training samples Ns, and (f) number of training epochs Ne. For all tests, the… view at source ↗
Figure 18
Figure 18. Figure 18: Convergence behaviour of GMRES for 100 × 100 finite-difference dis￾cretisations of the diffusion equation, without preconditioner (left) and with the NGO-based preconditioner (right). Each line corresponds to one linear system being solved [PITH_FULL_IMAGE:figures/full_fig_p030_18.png] view at source ↗
Figure 19
Figure 19. Figure 19: Convergence behaviour of GMRES for 100 ×100 finite-difference discreti￾sations of the diffusion equation, with only a block-Jacobi preconditioner (left) and with both a block-Jacobi and NGO-based preconditioner (right). Each line corre￾sponds to one linear system being solved. 5 Extension to Other Problems 5.1 Time-Dependent Diffusion The last test problem we consider is a time-dependent diffusion problem… view at source ↗
Figure 20
Figure 20. Figure 20: The space-time domain Ω × [0, T], with Neumann boundaries ΓN on the top and bottom, Dirichlet boundaries ΓD on the sides, and the initial condition boundary t = 0 on the left side. solution to problem (5.1) can be expressed in terms of a Green’s operator as u(x, t) = Z Ω,T G[θ]f dx ′ dt′ − Z ΓN,T G[θ]ηdx ′ dt′ + Z ΓD,T gˆn · ∇G[θ]dx ′ dt′ − Z Ω G[θ](t = 0)u0dx ′ . (5.2) The derivation of Equation (5.2) is… view at source ↗
Figure 21
Figure 21. Figure 21: Relative L2 test error versus test data (a) time scale τ /T and (b) length scale λ/L for a bare NN (here a U-Net), and the same NN, when used in a DeepONet, VarMiON, data NGO, data-free NGO and model NGO. Trends are similar to those in [PITH_FULL_IMAGE:figures/full_fig_p034_21.png] view at source ↗
Figure 22
Figure 22. Figure 22: Example of a manufactured solution u with length and time scales λ/L = 0.1 and τ /T = 0.1, together with the projection u p onto the 4x10x10 B-spline basis, and the solution ˆu predicted by the model NGO. The manufactured solution is based on θ and u, defined as in Equation 3.13, where bu ∼ U(−1, 1), cu ∼ U(0, 1), bθ = 1, cθ ∼ U(0, 0.2). • Model NGOs construct the input matrix using the weak form from Baz… view at source ↗
Figure 23
Figure 23. Figure 23: A plot showing the mean relative error of FNO, CNO, data NGO, and [PITH_FULL_IMAGE:figures/full_fig_p037_23.png] view at source ↗
Figure 24
Figure 24. Figure 24: From top to bottom: architectures of the DeepONet, FNO, and VarMiON. [PITH_FULL_IMAGE:figures/full_fig_p046_24.png] view at source ↗
Figure 25
Figure 25. Figure 25: Architecture of the model-based NGO (top) and data-based NGO (bot [PITH_FULL_IMAGE:figures/full_fig_p047_25.png] view at source ↗
Figure 26
Figure 26. Figure 26: UNet (system) architectures of the VarMiON (top left), Data-NGO (top [PITH_FULL_IMAGE:figures/full_fig_p048_26.png] view at source ↗
read the original abstract

This work introduces a paradigm for constructing parametric neural operators that are derived from finite-dimensional representations of Green's operators for linear partial differential equations (PDEs). We refer to such neural operators as Neural Green's Operators (NGOs). Our construction of NGOs preserves the linear action of Green's operators on the inhomogeneity fields, while approximating the nonlinear dependence of the Green's function on the coefficients of the PDE using neural networks. This construction reduces the complexity of the problem from learning the entire solution operator and its dependence on all parameters to only learning the Green's function and its dependence on the PDE coefficients. Furthermore, we show that our explicit representation of Green's functions enables the embedding of desirable mathematical attributes in our NGO architectures, such as symmetry, spectral, and conservation properties. Through numerical benchmarks on canonical PDEs, we demonstrate that NGOs achieve comparable or superior accuracy to Deep Operator Networks, Variationally Mimetic Operator Networks, and Fourier Neural Operators with similar parameter counts, while generalizing significantly better when tested on out-of-distribution data. For parametric time-dependent PDEs, we show that NGOs that are trained on a single time step can produce pointwise-accurate dynamics in an auto-regressive manner over arbitrarily large numbers of time steps. For parametric nonlinear PDEs, we demonstrate that NGOs trained exclusively on solutions of corresponding linear problems can be embedded within iterative solvers to yield accurate solutions, provided a suitable initial guess is available. Finally, we show that we can leverage the explicit representation of Green's functions returned by NGOs to construct effective matrix preconditioners that accelerate iterative solvers for PDEs.

Editorial analysis

A structured set of objections, weighed in public.

Desk editor's note, referee report, simulated authors' rebuttal, and a circularity audit. Tearing a paper down is the easy half of reading it; the pith above is the substance, this is the friction.

Referee Report

0 major / 2 minor

Summary. The manuscript introduces Neural Green's Operators (NGOs) as parametric neural operators derived from finite-dimensional representations of Green's operators for linear PDEs. The construction exactly preserves the linear action of the Green's operator on inhomogeneity fields while using neural networks to approximate the nonlinear dependence of the Green's function on PDE coefficients. This reduces the learning task and enables embedding of mathematical properties such as symmetry, spectral, and conservation attributes. Numerical benchmarks on canonical PDEs show NGOs achieving comparable or superior accuracy to DeepONet, VMON, and FNO with similar parameter counts and significantly better out-of-distribution generalization. Additional results cover auto-regressive time-stepping for time-dependent PDEs trained on single steps, embedding in iterative solvers for nonlinear PDEs, and construction of effective preconditioners from the explicit Green's function representations.

Significance. If the results hold, the work offers a principled way to incorporate classical Green's function theory into neural operator learning, separating linear action (preserved exactly) from nonlinear coefficient dependence (learned). This structure could improve generalization and enable embedding of desirable properties, with practical extensions to time-dependent problems, nonlinear solvers, and preconditioning. The approach stands out for reducing the learning problem while maintaining mathematical fidelity, potentially influencing future operator architectures for parametric PDEs.

minor comments (2)
  1. [Abstract] The abstract refers to 'canonical PDEs' without naming them; adding the specific equations (e.g., Poisson, heat, wave) would improve immediate readability.
  2. Notation for the finite-dimensional Green's operator representation and its discretization could be introduced with a brief example in the introduction or early methods section to aid readers unfamiliar with the construction.

Simulated Author's Rebuttal

0 responses · 0 unresolved

We thank the referee for their accurate summary of the manuscript and for recommending acceptance. No major comments were raised in the report.

Circularity Check

0 steps flagged

No significant circularity detected

full rationale

The paper constructs NGOs from finite-dimensional Green's operator representations for linear PDEs, preserving the exact linear action on inhomogeneity fields while using NNs only to approximate nonlinear coefficient dependence. This separation follows directly from classical Green's function theory without reduction to fitted inputs or self-referential definitions. Benchmarks compare against external baselines (DeepONet, FNO, etc.) on out-of-distribution data, and extensions (auto-regressive stepping, iterative solvers) are presented with explicit caveats. No load-bearing step equates a prediction to its own inputs by construction, and no self-citation chain is invoked for uniqueness or ansatz. The derivation remains self-contained against external mathematical and numerical evidence.

Axiom & Free-Parameter Ledger

0 free parameters · 1 axioms · 0 invented entities

Review performed on abstract only; full details on free parameters, axioms, and invented entities are unavailable. The abstract invokes standard Green's operator theory for linear PDEs and neural network approximation of coefficient dependence.

axioms (1)
  • domain assumption Green's operators exist and admit finite-dimensional representations for the linear PDEs under consideration
    Invoked implicitly when stating that NGOs are derived from such representations.

pith-pipeline@v0.9.0 · 5810 in / 1313 out tokens · 26173 ms · 2026-05-24T00:23:28.084750+00:00 · methodology

discussion (0)

Sign in with ORCID, Apple, or X to comment. Anyone can read and Pith papers without signing in.

Lean theorems connected to this paper

Citations machine-checked in the Pith Canon. Every link opens the source theorem in the public Lean library.

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.

Forward citations

Cited by 1 Pith paper

Reviewed papers in the Pith corpus that reference this work. Sorted by Pith novelty score.

  1. On the definition and importance of interpretability in scientific machine learning

    cs.LG 2025-05 conditional novelty 6.0

    Interpretability in SciML requires mechanistic understanding rather than sparsity, and prior knowledge is often essential for interpretable scientific discovery.

Reference graph

Works this paper leans on

29 extracted references · 29 canonical work pages · cited by 1 Pith paper · 1 internal anchor

  1. [1]

    The variational multiscale method—a paradigm for computational mechanics

    Thomas JR Hughes, Gonzalo R Feij´ oo, Luca Mazzei, and Jean-Baptiste Quincy. The variational multiscale method—a paradigm for computational mechanics. Computer methods in applied mechanics and engineering , 166(1-2):3–24, 1998

  2. [2]

    The finite element method: linear static and dynamic finite element analysis

    Thomas JR Hughes. The finite element method: linear static and dynamic finite element analysis. Courier Corporation, 2012

  3. [3]

    Computational fluid dynamics , volume

    John David Anderson and John Wendt. Computational fluid dynamics , volume

  4. [4]

    Computational fluid- structure interaction: methods and applications

    Yuri Bazilevs, Kenji Takizawa, and Tayfun E Tezduyar. Computational fluid- structure interaction: methods and applications . John Wiley & Sons, 2013

  5. [5]

    Classical and computational solid mechanics

    Yuan-cheng Fung, Pin Tong, and Xiaohong Chen. Classical and computational solid mechanics. World Scientific, 2001

  6. [6]

    A comprehensive and fair comparison of two neural operators (with practical extensions) based on fair data

    Lu Lu, Xuhui Meng, Shengze Cai, Zhiping Mao, Somdatta Goswami, Zhongqiang Zhang, and George Em Karniadakis. A comprehensive and fair comparison of two neural operators (with practical extensions) based on fair data. Computer Methods in Applied Mechanics and Engineering , 393:114778, 2022

  7. [7]

    Multilayer feedforward networks are universal approximators

    Kurt Hornik, Maxwell Stinchcombe, and Halbert White. Multilayer feedforward networks are universal approximators. Neural networks, 2(5):359–366, 1989

  8. [8]

    Universal approximation to nonlinear operators by neural networks with arbitrary activation functions and its application to dynamical systems

    Tianping Chen and Hong Chen. Universal approximation to nonlinear operators by neural networks with arbitrary activation functions and its application to dynamical systems. IEEE transactions on neural networks , 6(4):911–917, 1995

  9. [9]

    Learning nonlinear operators via deeponet based on the universal ap- proximation theorem of operators

    Lu Lu, Pengzhan Jin, Guofei Pang, Zhongqiang Zhang, and George Em Karni- adakis. Learning nonlinear operators via deeponet based on the universal ap- proximation theorem of operators. Nature machine intelligence , 3(3):218–229, 2021

  10. [10]

    Fourier Neural Operator for Parametric Partial Differential Equations

    Zongyi Li, Nikola Kovachki, Kamyar Azizzadenesheli, Burigede Liu, Kaushik Bhattacharya, Andrew Stuart, and Anima Anandkumar. Fourier neu- ral operator for parametric partial differential equations. arXiv preprint arXiv:2010.08895, 2020. 39

  11. [11]

    Multipole graph neu- ral operator for parametric partial differential equations

    Zongyi Li, Nikola Kovachki, Kamyar Azizzadenesheli, Burigede Liu, Andrew Stuart, Kaushik Bhattacharya, and Anima Anandkumar. Multipole graph neu- ral operator for parametric partial differential equations. Advances in Neural Information Processing Systems, 33:6755–6766, 2020

  12. [12]

    Neural operator: Learning maps between function spaces with applications to pdes

    Nikola Kovachki, Zongyi Li, Burigede Liu, Kamyar Azizzadenesheli, Kaushik Bhattacharya, Andrew Stuart, and Anima Anandkumar. Neural operator: Learning maps between function spaces with applications to pdes. Journal of Machine Learning Research, 24(89):1–97, 2023

  13. [13]

    Machine learning–accelerated computational fluid dynam- ics

    Dmitrii Kochkov, Jamie A Smith, Ayya Alieva, Qing Wang, Michael P Brenner, and Stephan Hoyer. Machine learning–accelerated computational fluid dynam- ics. Proceedings of the National Academy of Sciences , 118(21):e2101784118, 2021

  14. [14]

    Fourier neural operator based fluid-structure interaction for predicting the vesicle dynamics

    Wang Xiao, Ting Gao, Kai Liu, Jinqiao Duan, and Meng Zhao. Fourier neural operator based fluid-structure interaction for predicting the vesicle dynamics. arXiv preprint arXiv:2401.02311 , 2024

  15. [15]

    Physics-guided, physics- informed, and physics-encoded neural networks and operators in scientific com- puting: Fluid and solid mechanics

    Salah A Faroughi, Nikhil M Pawar, C´ elio Fernandes, Maziar Raissi, Subasish Das, Nima K Kalantari, and Seyed Kourosh Mahjour. Physics-guided, physics- informed, and physics-encoded neural networks and operators in scientific com- puting: Fluid and solid mechanics. Journal of Computing and Information Science in Engineering, 24(4):040802, 2024

  16. [16]

    Fourier neural operator for accurate optical fiber modeling with low complexity

    Xingchen He, Lianshan Yan, Lin Jiang, Anlin Yi, Zhengyu Pu, Youren Yu, Hongwei Chen, Wei Pan, and Bin Luo. Fourier neural operator for accurate optical fiber modeling with low complexity. Journal of Lightwave Technology , 41(8):2301–2311, 2022

  17. [17]

    Green’s functions for preconditioning

    Daniel Loghin. Green’s functions for preconditioning. 1999

  18. [18]

    Mathe- matical methods for physics and engineering: a comprehensive guide

    Kenneth Franklin Riley, Michael Paul Hobson, and Stephen John Bence. Mathe- matical methods for physics and engineering: a comprehensive guide. Cambridge university press, 2006

  19. [19]

    Principled inter- polation of green’s functions learned from data

    Harshwardhan Praveen, Nicolas Boull´ e, and Christopher Earls. Principled inter- polation of green’s functions learned from data. Computer Methods in Applied Mechanics and Engineering, 409:115971, 2023

  20. [20]

    Learning green’s func- tions of linear reaction-diffusion equations with application to fast numerical 40 solver

    Yuankai Teng, Xiaoping Zhang, Zhu Wang, and Lili Ju. Learning green’s func- tions of linear reaction-diffusion equations with application to fast numerical 40 solver. In Mathematical and Scientific Machine Learning , pages 1–16. PMLR, 2022

  21. [21]

    Deep generalized green’s functions

    Rixi Peng, Juncheng Dong, Jordan Malof, Willie J Padilla, and Vahid Tarokh. Deep generalized green’s functions. arXiv preprint arXiv:2306.02925 , 2023

  22. [22]

    Deepgreen: deep learning of green’s functions for nonlinear boundary value problems

    Craig R Gin, Daniel E Shea, Steven L Brunton, and J Nathan Kutz. Deepgreen: deep learning of green’s functions for nonlinear boundary value problems. Sci- entific reports, 11(1):21614, 2021

  23. [23]

    Variationally mimetic operator networks

    Dhruv Patel, Deep Ray, Michael RA Abdelmalik, Thomas JR Hughes, and Assad A Oberai. Variationally mimetic operator networks. Computer Methods in Applied Mechanics and Engineering , 419:116536, 2024

  24. [24]

    Con- volutional neural operators for robust and accurate learning of pdes

    Bogdan Raonic, Roberto Molinaro, Tim De Ryck, Tobias Rohner, Francesca Bartolucci, Rima Alaifari, Siddhartha Mishra, and Emmanuel de B´ ezenac. Con- volutional neural operators for robust and accurate learning of pdes. Advances in Neural Information Processing Systems , 36, 2024

  25. [25]

    Weak imposition of dirichlet boundary conditions in fluid mechanics

    Yuri Bazilevs and Thomas JR Hughes. Weak imposition of dirichlet boundary conditions in fluid mechanics. Computers & fluids , 36(1):12–26, 2005

  26. [26]

    Fourier neural operator with learned deformations for pdes on general geome- tries

    Zongyi Li, Daniel Zhengyu Huang, Burigede Liu, and Anima Anandkumar. Fourier neural operator with learned deformations for pdes on general geome- tries. Journal of Machine Learning Research , 24(388):1–26, 2023

  27. [27]

    Nutils, November 2023

    Joost Simon Boudewijn van Zwieten, Gerrit Johannes van Zwieten, and Wijnand Hoitinga. Nutils, November 2023

  28. [28]

    Generating synthetic data for neural opera- tors

    Erisa Hasani and Rachel A Ward. Generating synthetic data for neural opera- tors. arXiv preprint arXiv:2401.02398 , 2024. A Derivation of Green’s operators A.1 Steady diffusion To derive the Green’s operator for the steady diffusion equation 4.4 as given by equation 4.2, we follow the approach of Section 2. We start with testing the governing equation aga...

  29. [29]

    For the VarMiON and NGO, the normalisation doesn’t affect the model accuracy since these models are linear in f and η

    This normalisation was done to ensure that the inputs η, θ, f are of a similar magnitude to what they are in the training data. For the VarMiON and NGO, the normalisation doesn’t affect the model accuracy since these models are linear in f and η. However, DeepONets and FNOs, which do not have this linearity, are expected to perform best when the inputs ar...