Pith. sign in

REVIEW 2 major objections 5 minor 35 references

Walk-on-Spheres Monte Carlo and deep neural network approximations of elliptic PDEs with drift and killing

T0 review · 2 major / 5 minor · reviewed 2026-08-11 · deepseek-v4-flash

Pith's one-line read A modified Walk-on-Spheres estimator with sampled random times approximates elliptic PDEs with drift and killing uniformly, with Monte Carlo and ReLU-network cost polynomial in accuracy and dimension.

desk verdict The Monte Carlo half is solid and genuinely extends the Beznea-Grohs framework to drift and killing; the ANN half is a conditional bound on an uninstantiated distance-function hypothesis, and the abstract oversells the ANN claim. read the letter →

arxiv 2608.09494 v1 pith:64HMUUMF submitted 2026-08-10 math.NA cs.LGcs.NAmath.APmath.PR

classification math.NAcs.LGcs.NAmath.APmath.PR MSC 65C0565N7535J1568T07
keywords Walk-on-SpheresellipticPDEwithdriftandkillingMonteCarloestimatordeepneuralnetworkapproximationReLUnetworkscurseofdimensionalityFeynman-Kacrepresentationuniformerrorbounds
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 proves that a modified Walk-on-Spheres Monte Carlo estimator, and a ReLU neural network built from it, approximate the solution of linear elliptic PDEs with constant diffusion, drift, and killing uniformly over a bounded convex domain. The estimator adds sampled random times to the classical scheme, and those times are what compensate the drift and killing terms in the Feynman-Kac representation. The main error bound says that for a prescribed accuracy $\varepsilon$ the number of Monte Carlo paths and steps grows at most polynomially in $1/\varepsilon$ and the dimension $d$. The neural-network theorem proves the boundary-payoff part $w(x)=\mathbb{E}[h(\tau^x,x+B_{\tau^x})]$ is ReLU-approximable with parameter count polynomial in $1/\varepsilon$ and $d$, assuming the boundary data and distance-to-boundary are network-approximable, with the source-term case noted as an extension. If correct, this moves a broader class of high-dimensional elliptic boundary value problems out of the curse-of-dimensionality regime.

What carries the argument

The load-bearing object is the modified Walk-on-Spheres process driven by a $(\beta,\delta)$-distance: a Lipschitz function $\bar{r}$ that stays below the true boundary distance $r$ and keeps at least a $\beta$ fraction of it until the process is within $\delta$ of the boundary. At each step the process jumps uniformly on the sphere of radius $\bar{r}(\bar{X})$ around the current point, and the physical time $\bar{\tau}$ accumulates $\bar{r}(\bar{X})^2$ times independent copies of the exit time $\zeta$ of Brownian motion from the unit ball. This random time is what absorbs drift and killing in the representation. The companion mechanism is the time-space occupation measure $\mu$ of Lemma 3.8, which converts integrals over Brownian paths inside the unit ball into expectations of samples $(V_k,Y_k)$, so the estimator (5) becomes a plain average of i.i.d. path functionals. The analysis rests on three estimates: a geometric tail bound on the number of steps needed to come within $\delta$ of the boundary, a bias bound with terms of order $\delta$ and $\delta^{1/2}$, and a concentration bound that controls the supremum over the domain through a grid whose size is polynomial in $M$ and the Lipschitz constant of $\bar{r}$.

What would settle it

Find a bounded convex domain $D$ and a ReLU-representable boundary datum $h$ for which $\mathrm{dist}(\cdot,\partial D)$ cannot be uniformly $\varepsilon$-approximated by ReLU networks of size $O(\varepsilon^{-\eta})$ for any absolute constant $\eta$; then the parameter bound of Theorem 5.6 fails for that domain. At the Monte Carlo level, compute $\mathbb{E}[\tau^x]$ and the $\delta^{1/2}$ bias term of Lemma 4.1 on a long thin rectangle to test whether the convexity bound $\mathbb{E}[\tau^x]\le r(x)\operatorname{diam}(D)$ is the right mechanism.

Watch

Extended reading notes

Core claim

On the paper's own terms, the central discovery is that the stochastic representation $w(x)=\mathbb{E}[h_0(\tau^x,x+B_{\tau^x})]+\mathbb{E}[\int_0^{\tau^x} h_1(s,x+B_s)\,ds]$ of solutions to (2) can be evaluated by the Walk-on-Spheres estimator (5), in which each step's physical time is accumulated as $\bar{r}(\bar{X})^2$ times the exit time of Brownian motion from the unit sphere. For bounded Lipschitz $h_0,h_1$ and a $(\beta,\delta)$-distance $\bar{r}$, Corollary 4.10 gives $\mathbb{E}[\sup_{x\in D}|w(x)-\bar{w}(x)|]\le\varepsilon$ with $\max\{n,M\}\le c\,d^q\varepsilon^{-q}$, where $q$ is an absolute constant and $c$ depends at most polynomially on the problem data. Theorem 5.6 shows that when $h_0$ is representable by an ANN and the boundary-distance function is uniformly approximated by ReLU networks satisfying (138), there exists a ReLU network $\Psi_\varepsilon$ whose realization $R(\Psi_\varepsilon)$ satisfies $\sup_{x\in D}|w(x)-R(\Psi_\varepsilon)(x)|\le\varepsilon$ with $P(\Psi_\varepsilon)\le c\varepsilon^{-q}$. The link to the PDE is a Girsanov-based Feynman-Kac formula, after which the multiplier $e^{-\langle b,x\rangle}$ converts $w$ into the solution of (2).

Load-bearing premise

The neural-network half stands on the unverified hypothesis that the distance to the boundary can be uniformly approximated to accuracy $\varepsilon$ by ReLU networks of size $C\varepsilon^{-\eta}$ with an absolute constant $\eta$; the Monte Carlo half separately requires $D$ to be convex, so nonconvex exterior-ball domains are out of reach.

Editorial extensions

If this is right

  • On any bounded convex domain with bounded Lipschitz data, the drift-killing elliptic PDE (2) can be approximated to uniform accuracy $\varepsilon$ by Monte Carlo with sample and step counts polynomial in $\varepsilon^{-1}$ and $d$.
  • Whenever the boundary data and the distance-to-boundary are ReLU-representable with polynomial-size networks, the solution's boundary-payoff part is ReLU-approximable with polynomial parameter count, breaking the curse of dimensionality on this class.
  • The same estimator structure covers the source term $h_1\neq 0$ in the Monte Carlo half, and the authors indicate the neural construction extends to that case as well.
  • The deterministic $M$-step stopping rule gives the approximating network a fixed depth for each target accuracy, which is what makes the ANN construction feasible.

Reading between the lines

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

  • The neural-network theorem does not exhibit a concrete domain where hypothesis (138) holds; constructing explicit ReLU approximations of $\mathrm{dist}(\cdot,\partial D)$ for high-dimensional balls, cubes, or polytopes and measuring the actual exponent $\eta$ would determine how widely the polynomial parameter bound applies.
  • The Monte Carlo half assumes convexity of $D$ to get $\mathbb{E}[\tau^x]\le r(x)\operatorname{diam}(D)$; if a similar exit-time bound holds under the weaker exterior ball condition used in the drift-free predecessor, the method would extend to nonconvex domains.
  • The use of sampled random times suggests a general recipe for other Feynman-Kac-type estimators: any additive functional of Brownian exit can be turned into an i.i.d. path average by sampling the time-space occupation of the unit ball, not just the exit position.
Share X Bluesky LinkedIn Reddit HN

Editorial analysis

A structured set of objections, weighed in public.

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

Referee Report

2 major / 5 minor

Summary. The paper studies the numerical approximation of functions w(x) = E[h0(τ^x, x + B_{τ^x})] + E[∫_0^{τ^x} h1(s, x + B_s) ds] on bounded convex domains D, which arise as stochastic representations of solutions of linear elliptic PDEs with constant diffusion, drift, and killing (Eq. (1), Prop. 2.2). The authors extend the modified Walk-on-Spheres framework of Beznea et al. [6] by explicitly including the sampled exit times needed for drift and killing, construct Monte Carlo estimators of the form (5), and prove a uniform L∞ error bound (Thm. 4.9) together with a polynomial complexity statement (Cor. 4.10). They then prove an ANN approximation result (Thm. 5.6) for the case h1 ≡ 0, under the assumptions that the boundary data are representable by an ANN and that the distance-to-boundary function is uniformly approximable by ReLU networks with a certain rate (condition (138)). The paper concludes with remarks on overcoming the curse of dimensionality.

Significance. If the results hold, the Monte Carlo half is a solid contribution: it extends the uniform-error complexity analysis of [6] and [11] to drift-diffusion-reaction equations, with sample complexity polynomial in 1/ε and, under explicit growth assumptions, in the dimension d. The proof chain for the Monte Carlo part is detailed and appears sound, including the Itô-based moment estimates (Lemmas 3.6, 3.7), the bias decomposition (Lemmas 4.1, 4.2), and the randomized grid argument in Theorem 4.9. The ANN half is more delicate: Theorem 5.6 is a conditional statement whose central hypothesis (138) is not instantiated for any concrete domain or class of domains, and as written the proof contains a parameter inconsistency around Eq. (145). The paper is therefore best assessed as a partially conditional extension of known techniques rather than a fully unconditional resolution of the high-dimensional approximation problem.

major comments (2)
  1. [§5.3, Theorem 5.6, condition (138) and Remark 5.7] The main ANN result rests on the assumption that for every ε ∈ (0,1) the function r(x) = dist(x, ∂D) is uniformly approximated by ReLU networks r_ε with P(r_ε) ≤ C ε^{-η} for an absolute constant η and a uniform Lipschitz constant C. The paper neither proves this for any domain D nor cites a class of domains for which it holds. For a generic convex domain, r is only 1-Lipschitz, and the standard ReLU approximation rate for d-variate Lipschitz functions is of order ε^{-d}, which would make η dimension-dependent. In that case the conclusion P(Ψ_ε) ≤ c ε^{-q} still holds for each fixed d, but the dimension dependence is absorbed into c (or q), and the 'overcoming the curse of dimensionality' claim in Remark 5.7(i) is not established. The authors should either prove (138) for explicit non-trivial examples (e.g., Euclidean balls or convex polytopes), or substantially weaken the interpretation of the theorem as a purely conditional result.
  2. [§5.3, Eq. (145)] In the proof of Theorem 5.6, the network b_ε is defined by R(b_ε)(x) = ((R(r_{δ_ε/3}))(x) − ε)_+ and is then claimed to be a (1/3, δ_ε)-distance. With the parameter choice in (140), δ_ε is typically much smaller than ε (frequently δ_ε ≈ ε^2), so for a point x with r(x) ≥ δ_ε the lower bound R(b_ε)(x) ≥ δ_ε/3 is not guaranteed: subtracting ε instead of δ_ε/3 can make the positive part vanish. The intended definition is almost certainly R(b_ε)(x) = ((R(r_{δ_ε/3}))(x) − δ_ε/3)_+, which does combine with the approximation error in (138) to yield a (1/3, δ_ε)-distance. As written, however, the application of Corollary 4.10 at (150) is not justified, so this is a load-bearing point that must be corrected.
minor comments (5)
  1. [§4.2, Lemma 4.4] In the proof of Lemma 4.4(ii), the displayed bound for |τ̂{x,i}_k − τ̂{y,i}_k| contains a repeated index in the term ∥X̂{x,i}_{k−1} − X̂{x,i}_{k−1}∥; the second superscript should be y, not x. This is a harmless typo but should be fixed.
  2. [§3, Lemma 3.6] The definition of w in Eq. (32) would be clearer with explicit parentheses, e.g., w(x) = 1 − γ∥x∥²/(d + γr²), since the intended reading is used immediately afterward in the proof.
  3. [§4.2, Theorem 4.9] The bound (108) is extremely long and difficult to parse. Splitting it into named aggregate terms, as is partially done in the proof, would improve readability without changing the mathematics.
  4. [§5.3, Remark 5.7(iii)] The extension to h1 ≠ 0 is only sketched, while the abstract and introduction highlight the drift-killing class of PDEs more broadly. A precise statement of the h1 ≠ 0 ANN result, even as a corollary, would make the paper's claims easier to verify.
  5. [References] Reference [6] is cited as the arXiv preprint arXiv:2209.01432; if a published version now exists, it should be cited in its final form.

Circularity Check

0 steps flagged · score 1.0 of 10

No significant circularity: Monte Carlo bounds are derived self-containedly and the ANN result is an explicit conditional theorem; only minor non-load-bearing self-citations appear.

full rationale

The paper is a pure derivation: all error and complexity bounds are obtained analytically from explicit assumptions, with no fitted parameters, no data, and no prediction-that-is-a-fit. The Monte Carlo half (Theorem 4.9 and Corollary 4.10) is self-contained given convexity, the (β, δ)-distance hypothesis, and the Lipschitz/boundedness hypotheses; the key geometric input E[τ^x] ≤ r(x) diam(D) (Lemma 3.2) is explicitly attributed to [11, Lemma 3.2], whose authors do not overlap with the present authors, and the modified Walk-on-Spheres framework is attributed to [6] (Beznea et al.), also external. The ANN half (Theorem 5.6) is conditional on the explicit hypothesis (138) on ReLU approximation of the distance-to-boundary function; this is a stated assumption, not a derived conclusion, and the theorem is proved by composing the separately established Monte Carlo bounds with ANN calculi from [13], [17], [1], and Yarotsky's product approximation. The only self-citations ([4], [16]) are used for standard ANN composition/architecture lemmas (e.g., [16, Lemma 3.3] in the parameter bound of Theorem 5.6); they are not the source of the PDE approximation statement and do not carry the central claim. The conditional nature of Theorem 5.6 on (138) is a support/correctness question — no domain is instantiated — but that is a missing hypothesis check, not circularity. No equation is defined in terms of another in a way that makes a prediction equal to its input, no fitted parameter is relabeled a prediction, and no uniqueness claim is imported from the authors' prior work. Score 1 reflects only the presence of minor, non-load-bearing self-citations.

Assumptions & free parameters 0 free parameters · 6 assumptions · 0 invented entities

No free parameters: nothing is fitted to data; the paper proves existence and complexity statements with explicit functions or absolute constants. No invented entities: the modified distance functions come from [6], and the random objects (V_k, Y_k), ρ, ξ are standard Brownian functionals. The six axioms above are the load-bearing premises, of which (138) is the least supported.

assumptions (6)
  • domain assumption D is open, bounded, and convex, with an exterior ball condition assumed only for classical PDE existence (Remark 2.1).
    Convexity enters at the opening of Section 4 and is used in Lemma 3.2 (E[τ^x] ≤ r(x)·diam(D)), which drives the δ and δ^{1/2} bias terms in Lemmas 4.1 and 4.2. This is more restrictive than the exterior ball condition used in [6].
  • domain assumption Existence of a (β,δ)-distance ṝ (Definition 3.3, inherited from [6, Definition 2.7]): Lipschitz, ṝ ≤ r pointwise, and ṝ ≥ βr whenever r ≥ δ.
    Controls the walk-on-spheres step count through Lemma 3.7's tail bound; β^{-1} enters the complexity constants of Corollary 4.10. The true distance function itself qualifies with β = 1, so the assumption is mild for the Monte Carlo part.
  • standard math Standard stochastic calculus: Itô's formula, optional stopping theorem, strong Markov property, Girsanov theorem, and Brownian scaling.
    Used in Proposition 2.2 (Itô product rule and localization), Lemma 3.1, Lemma 3.4 (strong Markov property and induction), Lemma 3.6, and Remark 2.3 (Girsanov).
  • standard math E[ζ] = 1/d for the unit sphere exit time, and uniqueness of the rotationally invariant probability measure on the unit sphere.
    E[ζ] = 1/d is cited to [28, Proposition 2.2.21] and used in Lemmas 3.8, 4.5 and 4.7; rotational uniqueness is cited to [22, Theorem 3.4] in Lemma 3.1.
  • ad hoc to paper Theorem 5.6, condition (138): ANNs r_ε approximate dist(·,∂D) uniformly to error ≤ ε with P(r_ε) ≤ Cε^{-η} and a uniform Lipschitz constant C, for η an absolute constant.
    This hypothesis supplies the (1/3, δ_ε)-distance b_ε used in the ANN construction; without it the ANN complexity bound has no grounding. The paper does not show which concrete domain classes satisfy (138).
  • domain assumption Boundary data h (and h0, h1) are bounded and Lipschitz on [0,∞) × D; in Theorem 5.6, h is itself a neural network with Lipschitz constants L1, L2.
    Lipschitz propagation through the walk-on-spheres process (Lemma 4.6) and ANN composition (Lemma 5.5) require these conditions; Remark 2.5 shows the Girsanov-transformed h0 and h1 inherit them when r + ||b||²/2 ≥ 0 and D is bounded.

how reviews work

0 comments
Cite this review

Pith. "Pith review of Walk-on-Spheres Monte Carlo and deep neural network approximations of elliptic PDEs with drift and killing." pith.science (2026). https://pith.science/paper/64HMUUMF

@misc{pith2026260809494,
  author       = {Pith},
  title        = {Pith review of: Walk-on-Spheres Monte Carlo and deep neural network approximations of elliptic PDEs with drift and killing},
  year         = {2026},
  howpublished = {\url{https://pith.science/paper/64HMUUMF}},
  note         = {Machine review of arXiv:2608.09494}
}
read the original abstract

In this paper we provide Monte Carlo and deep neural network approximations for stochastic representations of solutions to linear elliptic partial differential equations with constant diffusion, drift and killing. Building on the modified Walk-on-Spheres algorithm of Beznea et al. (arXiv:2209.01432), we introduce Monte Carlo estimators that explicitly incorporate sampled random times arising in the analyzed stochastic representations. We establish uniform error bounds for these estimators and show that, under suitable assumptions, a prescribed approximation accuracy is achieved with sample complexities growing at most polynomially in both the inverse accuracy and the problem dimension. Furthermore, we prove a deep neural network approximation result for the stochastic representations. Assuming suitable neural network representations of the boundary data and the distance function to the boundary, we use the constructed Monte Carlo to design deep neural networks that approximate the representation uniformly with a number of parameters growing at most polynomially in the inverse accuracy and the problem dimension. These results extend previous complexity analyses to a broader class of elliptic equations involving drift and killing.

Discussion (0). Continue with ORCID to comment.

Reference graph

Works this paper leans on

35 extracted references · 29 canonical work pages

  1. [6]

    From Monte Carlo to neural networks approximations of boundary value problems

    Lucian Beznea, Iulian Cimpean, Oana Lupascu-Stamate, Ionel Popescu, and Arghir Zarnescu. From Monte Carlo to neural networks approximations of boundary value problems. arXiv:2209.01432, 2022

  2. [11]

    Deep neural network approximation for high-dimensional elliptic PDEs with boundary conditions

    Philipp Grohs and Lukas Herrmann. Deep neural network approximation for high-dimensional elliptic PDEs with boundary conditions. IMA J. Numer. Anal., 42(3):2055–2082, 2022

  3. [1]

    Julia Ackermann, Arnulf Jentzen, Thomas Kruse, Benno Kuckuck, and Joshua Lee Padgett. Deep neural networks with ReLU, leaky ReLU, and softplus activation provably overcome the curse of dimensionality for Kolmogorov partial differential equations with Lipschitz nonlinearities in thelp-sense. arXiv:2309.13722, 2023

  4. [2]

    Julia Ackermann, Arnulf Jentzen, Benno Kuckuck, and Joshua Lee Padgett. Deep neural networks with ReLU, leaky ReLU, and softplus activation provably overcome the curse of dimensionality for space-time solutions of semilinear partial differential equations. arXiv:2406.10876, 2024

  5. [3]

    An overview on deep learning-based approximation methods for partial differential equa- tions

    Christian Beck, Martin Hutzenthaler, Arnulf Jentzen, and Benno Kuckuck. An overview on deep learning-based approximation methods for partial differential equa- tions. Discrete Contin. Dyn. Syst. Ser. B, 28(6):3697–3746, 2023

  6. [4]

    Nonlinear MonteCarlo methodswith polynomial runtimeforBellman equationsof discretetime high-dimensional stochastic optimal control problems.Appl

    Christian Beck, Arnulf Jentzen, Konrad Kleinberg, and Thomas Kruse. Nonlinear MonteCarlo methodswith polynomial runtimeforBellman equationsof discretetime high-dimensional stochastic optimal control problems.Appl. Math. Optim., 91(1):26, 2025

  7. [5]

    Julius Berner, Philipp Grohs, and Arnulf Jentzen. Analysis of the generalization error: empirical risk minimization over deep artificial neural networks overcomes the curse of dimensionality in the numerical approximation of Black-Scholes partial differential equations. SIAM J. Math. Data Sci., 2(3):631–657, 2020

  8. [7]

    Thomas E. Booth. Exact Monte Carlo solution of elliptic partial differential equa- tions. J. Comput. Phys., 39(2):396–404, 1981

Show all 35 references
  1. [8]

    Deepneuralnetworks overcome the curse of dimensionality in the numerical approximation of semilinear partial differential equations.arXiv:2205.14398, 2022

    PetruCioica-Licht, MartinHutzenthaler, andPTobiasWerner. Deepneuralnetworks overcome the curse of dimensionality in the numerical approximation of semilinear partial differential equations.arXiv:2205.14398, 2022

  2. [9]

    Avner Friedman.Stochastic differential equations and applications. Vol. 1. Probabil- ityandMathematicalStatistics, Vol.28.AcademicPress[HarcourtBraceJovanovich, Publishers], New York-London, 1975

  3. [10]

    Trudinger.Elliptic partial differential equations of second order

    David Gilbarg and Neil S. Trudinger.Elliptic partial differential equations of second order. Classics in Mathematics. Springer-Verlag, Berlin, Heidelberg, 2001

  4. [12]

    A proof that artificial neural networks overcome the curse of dimensionality in the numerical approximation of Black–Scholes partial differential equations.Mem

    Philipp Grohs, Fabian Hornung, Arnulf Jentzen, and Philippe Von Wurstemberger. A proof that artificial neural networks overcome the curse of dimensionality in the numerical approximation of Black–Scholes partial differential equations.Mem. Amer. Math. Soc., 284(1410), 2023. 33

  5. [13]

    Space- time error estimates for deep neural network approximations for differential equa- tions

    Philipp Grohs, Fabian Hornung, Arnulf Jentzen, and Philipp Zimmermann. Space- time error estimates for deep neural network approximations for differential equa- tions. Adv. Comput. Math., 49(1):4, 2023

  6. [14]

    Deep neural network approxi- mations for solutions of PDEs based on Monte Carlo algorithms.Partial Differ

    Philipp Grohs, Arnulf Jentzen, and Diyora Salimova. Deep neural network approxi- mations for solutions of PDEs based on Monte Carlo algorithms.Partial Differ. Equ. Appl., 3(4):45, 2022

  7. [15]

    A proof that rectified deep neural networks overcome the curse of dimensionality in the numerical approximation of semilinear heat equations

    Martin Hutzenthaler, Arnulf Jentzen, Thomas Kruse, and Tuan Anh Nguyen. A proof that rectified deep neural networks overcome the curse of dimensionality in the numerical approximation of semilinear heat equations. Partial Differ. Equ. Appl., 1:1–34, 2020

  8. [16]

    Deep neural networks can provably solve Bellman equations for Markov decision processes without the curse of dimensionality

    Arnulf Jentzen, Konrad Kleinberg, and Thomas Kruse. Deep neural networks can provably solve Bellman equations for Markov decision processes without the curse of dimensionality. arXiv:2506.22851, 2025

  9. [17]

    Mathe- matical introduction to deep learning: Methods, implementations, and theory

    Arnulf Jentzen, Benno Kuckuck, and Philippe von Wurstemberger. Mathe- matical introduction to deep learning: Methods, implementations, and theory. arXiv:2310.20360, 2023

  10. [18]

    Arnulf Jentzen, Diyora Salimova, and Timo Welti. A proof that deep artificial neural networks overcome the curse of dimensionality in the numerical approximation of Kolmogorov partial differential equations with constant diffusion and nonlinear drift coefficients. Commun. Math...

  11. [19]

    Shreve.Brownian motion and stochastic calculus, volume 113 ofGraduate Texts in Mathematics

    Ioannis Karatzas and Steven E. Shreve.Brownian motion and stochastic calculus, volume 113 ofGraduate Texts in Mathematics. Springer-Verlag, New York, second edition, 1991

  12. [20]

    Probability theory

    Achim Klenke. Probability theory. Universitext. Springer, London, second edition, 2014

  13. [21]

    Unbiased‘walk-on-spheres’ MonteCarlomethodsforthe fractionalLaplacian

    AndreasE.Kyprianou, AnaOsojnik, andTonyShardlow. Unbiased‘walk-on-spheres’ MonteCarlomethodsforthe fractionalLaplacian. IMA J. Numer. Anal., 38(3):1550– 1578, 2018

  14. [22]

    Geometry of sets and measures in Euclidean spaces, volume 44 of Cambridge Studies in Advanced Mathematics

    Pertti Mattila. Geometry of sets and measures in Euclidean spaces, volume 44 of Cambridge Studies in Advanced Mathematics. Cambridge University Press, Cam- bridge, 1995. Fractals and rectifiability

  15. [23]

    Some continuous Monte Carlo methods for the Dirichlet problem

    Mervin E Muller. Some continuous Monte Carlo methods for the Dirichlet problem. The Annals of Mathematical Statistics, pages 569–589, 1956

  16. [24]

    Monte Carlo-Algorithmen

    ThomasMüller-Gronbach, ErichNovak, andKlausRitter. Monte Carlo-Algorithmen. Springer-Verlag, 2012

  17. [25]

    Rectified deep neural networks overcome the curse of dimensionality in the numerical approximation of gradient-dependent semi- linear heat equations.Commun

    Ariel Neufeld and Tuan Anh Nguyen. Rectified deep neural networks overcome the curse of dimensionality in the numerical approximation of gradient-dependent semi- linear heat equations.Commun. Math. Sci., 23(4):883–912, 2025. 34

  18. [26]

    Ariel Neufeld and Tuan Anh Nguyen. Multilevel Picard approximations and deep neural networks with ReLU, leaky ReLU, and softplus activation overcome the curse of dimensionality when approximating semilinear parabolic partial differential equa- tions in Lp-sense. J. Comput. App...

  19. [27]

    Deep ReLU neural networks overcome the curse of dimensionality when approximating semilinear partial integro- differential equations

    Ariel Neufeld, Tuan Anh Nguyen, and Sizhou Wu. Deep ReLU neural networks overcome the curse of dimensionality when approximating semilinear partial integro- differential equations. Anal. Appl. (Singap.), 23(7):1127–1178, 2025

  20. [28]

    Port and Charles J

    Sidney C. Port and Charles J. Stone.Brownian motion and classical potential the- ory. Probability and Mathematical Statistics. Academic Press [Harcourt Brace Jo- vanovich, Publishers], New York-London, 1978

  21. [29]

    Rectified deep neural networks overcome the curse of dimensionality for nonsmooth value functions in zero-sum games of nonlinear stiff systems

    Christoph Reisinger and Yufei Zhang. Rectified deep neural networks overcome the curse of dimensionality for nonsmooth value functions in zero-sum games of nonlinear stiff systems. Anal. Appl. (Singap.), 18(06):951–999, 2020

  22. [30]

    Sabelfeld

    Karl K. Sabelfeld. Random walk on spheres method for solving drift-diffusion prob- lems. Monte Carlo Methods Appl., 22(4):265–275, 2016

  23. [31]

    Sabelfeld and Anastasya Kireeva

    Karl K. Sabelfeld and Anastasya Kireeva. A new global random walk algorithm for calculation of the solution and its derivatives of elliptic equations with constant coefficients in an arbitrary set of points.Appl. Math. Lett., 107:106466, 9, 2020

  24. [32]

    Sabelfeld and Anastasya Kireeva

    Karl K. Sabelfeld and Anastasya Kireeva. A global random walk on spheres algorithm forcalculatingthesolutionanditsderivativesofthedrift-diffusion-reactionequations. Math. Methods Appl. Sci., 45(3):1420–1431, 2022

  25. [33]

    Sabelfeld and Denis Talay

    Karl K. Sabelfeld and Denis Talay. Integral formulation of the boundary value prob- lems and the method of random walk on spheres. Monte Carlo Methods Appl., 1(1):1–34, 1995

  26. [34]

    Grid-free monte carlo for pdes with spatially varying coefficients.ACM Trans

    Rohan Sawhney, Dario Seyb, Wojciech Jarosz, and Keenan Crane. Grid-free monte carlo for pdes with spatially varying coefficients.ACM Trans. Graph., 41(4), July 2022

  27. [35]

    Error bounds for approximations with deep ReLU networks.Neural Networks, 94:103–114, 2017

    Dmitry Yarotsky. Error bounds for approximations with deep ReLU networks.Neural Networks, 94:103–114, 2017. 35

Pith tools

Reviewed August 11, 2026 · model on record in the stance chip above.