In this article, we explore the concept of sparsification in the context of decomposable submodular functions. Sparsification refers to the process of reducing the number of elements in a set while preserving its overall structure or properties. In the context of submodular functions, sparsification involves selecting a subset of the elements that approximate the original function’s behavior while minimizing the number of elements used.
The article begins by introducing the concept of semi-norms and how they are used to define sparsifiers for general norms. The author then turns to the setting of decomposable submodular functions, where the goal is to construct a sparsifier that approximates the original function’s behavior while using as few elements as possible.
To achieve this goal, the author presents several results related to sparsification in the context of decomposable submodular functions. These results include bounds on the maximum deviation of the sparsifier from the original function and the construction of spectrally efficient sparsifiers using effective resistances. The author also discusses how these results can be used to construct more general sparsifiers for non-decomposable submodular functions.
Throughout the article, the author uses engaging metaphors and analogies to help readers understand complex concepts. For example, the author compares the process of sparsifying a function to solving a puzzle where some pieces are missing, and the goal is to fill in the blanks while preserving the overall structure of the puzzle.
In conclusion, this article provides a comprehensive overview of sparsification in the context of decomposable submodular functions. By using simple language and engaging analogies, the author demystifies complex concepts and makes them accessible to a wide range of readers. The article is well-structured, with each section building on the previous one to provide a cohesive and informative overview of the topic.