We propose a general matrix-valued multiple kernel learning framework for
high-dimensional nonlinear multivariate regression problems. This framework
allows a broad class of mixed norm regularizers, including those that induce
sparsity, to be imposed on a dictionary of vector-valued Reproducing Kernel
Hilbert Spaces. We develop a highly scalable and eigendecomposition-free
algorithm that orchestrates two inexact solvers for simultaneously learning
both the input and output components of separable matrix-valued kernels. As a
key application enabled by our framework, we show how high-dimensional causal
inference tasks can be naturally cast as sparse function estimation problems,
leading to novel nonlinear extensions of a class of Graphical Granger Causality
techniques. Our algorithmic developments and extensive empirical studies are
complemented by theoretical analyses in terms of Rademacher generalization
bounds.

提出了一种矩阵值多核学习框架，可用于高维非线性多元回归问题，并使用广泛的 Mixed Norm Regularizers 支持字典的向量值再现核希尔伯特空间上的疏松度约束；通过该框架，高维因果推断任务可被自然地看作稀疏函数估计问题进行，从而引出了一类新的图形 Granger 因果分析技术的非线性扩展。