2407.01745
Adaptive control of reaction-diffusion PDEs via neural operator-approximated gain kernels
Luke Bhana, Yuanyuan Shi, Miroslav Krstic
correctmedium confidence
- Category
- Not specified
- Journal tier
- Strong Field
- Processed
- Sep 28, 2025, 12:56 AM
- arXiv Links
- Abstract ↗PDF ↗
Audit review
The paper’s Theorem 4 and proof strategy are coherent and technically careful: it formulates the target system (with both parameter-mismatch and neural-approximation perturbations), employs a logarithmic Lyapunov functional V = 1/2 ln(1+||ŵ||^2) + (1/(2γ))||λ−λ̂||^2 tailored to neutralize cross terms via the projection update, and derives explicit thresholds ε* and γ*(ε,λ̄) ensuring boundedness and asymptotic regulation, along with the bound Γ(t) ≤ R(e^{ρΓ(0)} − 1) (eqs. (65)–(73) and subsequent proof) . The candidate solution matches several ingredients (approximate backstepping, projection update, resolvent bounds, and even reproduces the thresholds ε*, γ*) but shifts to a quadratic Lyapunov functional and claims exponential L^2-decay of ||ŵ||. That claim is not justified by the derived inequality and departs from the paper’s Barbalat-based asymptotic convergence (which does not claim exponential decay) . Moreover, the paper explicitly flags regularity assumptions (λ̂, λ̂_t ∈ Λ; differentiability of K̂_t) as strong and unverified a priori (left for future work), whereas the model glosses over these by invoking generic semigroup arguments without addressing the same regularity caveats . Net: the paper’s result is correct (conditional on its stated assumptions), while the model’s proof contains a substantive overclaim and gaps.
Referee report (LaTeX)
\textbf{Recommendation:} no revision \textbf{Journal Tier:} strong field \textbf{Justification:} This work provides a solid theoretical extension of neural-operator-based backstepping to adaptive control for parabolic PDEs. The proof is carefully constructed with a Lyapunov functional that is well matched to the perturbation structure, and it yields explicit, practically meaningful thresholds on NO accuracy and adaptation gains. The assumptions and limitations are transparently stated. The simulation evidence supports both stability and computational speed benefits.