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Learning nonlinear operators via DeepONet based on the universal approximation theorem of operators

Journal Article · · Nature Machine Intelligence
 [1];  [2];  [3];  [4];  [3]
  1. Massachusetts Inst. of Technology (MIT), Cambridge, MA (United States); Brown University
  2. Brown Univ., Providence, RI (United States); Chinese Academy of Sciences (CAS), Beijing (China)
  3. Brown Univ., Providence, RI (United States)
  4. Worcester Polytechnic Institute, MA (United States)

It is widely known that neural networks (NNs) are universal approximators of continuous functions. However, a less known but powerful result is that a NN with a single hidden layer can accurately approximate any nonlinear continuous operator. This universal approximation theorem of operators is suggestive of the structure and potential of deep neural networks (DNNs) in learning continuous operators or complex systems from streams of scattered data. Here, in this work, we thus extend this theorem to DNNs. We design a new network with small generalization error, the deep operator network (DeepONet), which consists of a DNN for encoding the discrete input function space (branch net) and another DNN for encoding the domain of the output functions (trunk net). We demonstrate that DeepONet can learn various explicit operators, such as integrals and fractional Laplacians, as well as implicit operators that represent deterministic and stochastic differential equations. We study different formulations of the input function space and its effect on the generalization error for 16 different diverse applications.

Research Organization:
Brown Univ., Providence, RI (United States)
Sponsoring Organization:
USDOE
Grant/Contract Number:
SC0019453
OSTI ID:
2281727
Alternate ID(s):
OSTI ID: 1853304
Journal Information:
Nature Machine Intelligence, Journal Name: Nature Machine Intelligence Journal Issue: 3 Vol. 3; ISSN 2522-5839
Publisher:
Springer NatureCopyright Statement
Country of Publication:
United States
Language:
English

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