# On the Definiteness of the Weighted Laplacian and its Connection to Effective Resistance

arXiv: https://arxiv.org/abs/1408.2187 · HTML: https://mlsanity.com/paper/1408.2187/

## Key facts

- Cited by 3 papers in the map (data through 14 Oct 2026).
- First posted on arXiv 10 Aug 2014.

## Built on by (most cited first, 3 of 3)

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- [A Thorough View of Exact Inference in Graphs from the Degree-4 Sum-of-Squares Hierarchy](https://mlsanity.com/paper/2102.08019/) (2021)
- [ImplicitSLIM and How it Improves Embedding-based Collaborative Filtering](https://mlsanity.com/paper/2406.00198/) (2024)

## Abstract (arXiv)

This work explores the definiteness of the weighted graph Laplacian matrix with negative edge weights. The definiteness of the weighted Laplacian is studied in terms of certain matrices that are related via congruent and similarity transformations. For a graph with a single negative weight edge, we show that the weighted Laplacian becomes indefinite if the magnitude of the negative weight is less than the inverse of the effective resistance between the two incident nodes. This result is extended to multiple negative weight edges. The utility of these results are demonstrated in a weighted consensus network where appropriately placed negative weight edges can induce a clustering behavior for the protocol.