Add xDeepONet family to experimental models

CHANGELOG.md

@@ -10,6 +10,14 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ### Added
 
+- Adds xDeepONet — the extended DeepONet family — to experimental models
+  (`physicsnemo.experimental.models.xdeeponet`).  Provides a config-driven
+  assembly of eight DeepONet-based architectures (DeepONet, U-DeepONet,
+  Fourier-DeepONet, Conv-DeepONet, Hybrid-DeepONet, MIONet, Fourier-MIONet,
+  and TNO) for 2D and 3D spatial domains, with composable Fourier / UNet /
+  Conv branches, multiple decoder types (MLP, Conv, temporal projection),
+  and automatic spatial padding.  Suitable for standalone operator learning
+  and autoregressive temporal bundling.
 - Adds GLOBE model (`physicsnemo.experimental.models.globe.model.GLOBE`),
   including new variant that uses a dual tree traversal algorithm to reduce the
   complexity of the kernel evaluations from O(N^2) to O(N).

physicsnemo/experimental/models/xdeeponet/__init__.py

@@ -0,0 +1,48 @@
+# SPDX-FileCopyrightText: Copyright (c) 2023 - 2026 NVIDIA CORPORATION & AFFILIATES.
+# SPDX-FileCopyrightText: All rights reserved.
+# SPDX-License-Identifier: Apache-2.0
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+"""xDeepONet — the extended DeepONet family.
+
+Config-driven assembly of eight DeepONet-based architectures sharing a
+common branch/trunk/decoder pattern:
+
+- ``deeponet``, ``u_deeponet``, ``fourier_deeponet``, ``conv_deeponet``,
+  ``hybrid_deeponet`` — single-branch variants.
+- ``mionet``, ``fourier_mionet`` — two-branch multi-input variants.
+- ``tno`` — Temporal Neural Operator (branch2 = previous solution).
+
+Both 2D and 3D spatial versions are provided.  :class:`DeepONetWrapper` and
+:class:`DeepONet3DWrapper` are the recommended entry points; see their class
+docstrings for usage examples and the branch/trunk configuration schema.
+"""
+
+from .branches import MLPBranch, SpatialBranch, SpatialBranch3D, TrunkNet
+from .deeponet import DeepONet, DeepONet3D
+from .wrappers import DeepONet3DWrapper, DeepONetWrapper
+
+__all__ = [
+    # Core architectures
+    "DeepONet",
+    "DeepONet3D",
+    # Convenience wrappers (recommended entry points)
+    "DeepONetWrapper",
+    "DeepONet3DWrapper",
+    # Building blocks
+    "TrunkNet",
+    "MLPBranch",
+    "SpatialBranch",
+    "SpatialBranch3D",
+]