A structured reference of algorithmic results on correlation clustering, organized by year and annotated with approximation ratio, computational model, and technique. Use the filters to browse by setting.
| Year↕ | Paper↕ | Setting | Approx / Result↕ | Technique | Notes |
|---|---|---|---|---|---|
| 2006 | Offline | O(log n) |
— | Arbitrary edge weights; general (non-complete) graphs. | |
| 2008 | Offline Streaming | 3 |
Pivot | The Pivot algorithm — the baseline for all subsequent work. Extends to insertion-only streams in random-order arrival. | |
| 2010 | Online Lower Bound | Ω(n) lower bound |
— | No sublinear competitive ratio is achievable online: upon arrival, it is unknown whether an edge is part of a clique or a bridge between two cliques. | |
| 2015 | Offline | 2.06 |
LP Pivot | LP rounded via pivot-based approach. All edges have ±1 weights. Best known poly-time result for over a decade. | |
| 2021 | Parallel / MPC | O(1) |
— | Linear time; constant approximation in O(1) parallel rounds. | |
| 2021 | Online | Constant |
Pivot | Semi-online model with O(1/ε) recourse per update. Studies robustness of Pivot under adversarial arrivals. | |
| 2021 | Streaming | 1 + ε |
— | Dynamic, single-pass, semi-streaming (Õ(n) space). Exponential time. Near-optimal approximation ratio in streaming. | |
| 2022 | Offline | O(1) |
— | Sublinear time via random sampling of vertex neighborhoods. Link TBD. | |
| 2022 | Parallel / MPC | 3 + ε |
— | O(1/ε) parallel rounds; breaks the sequential Pivot bottleneck in the MPC model. | |
| 2022 | Online | Constant |
— | Online with recourse; guarantees consistency between consecutive clusterings as the input evolves. | |
| 2023 | Streaming Lower Bound | cost estimation only |
— | Uses polylog(n) bits of space to estimate the clustering cost — does not find the clustering itself. Includes matching lower bounds. | |
| 2023 | Streaming | 5 |
— | Single-pass streaming; 5-approximation. | |
| 2023 | Streaming | 3 + ε |
Pivot | Insertion-only, single pass. Pivot-based; simple and practical. | |
| 2023 | Offline | 1.73 |
LP | LP-based; O(n1/εO(1)) time. Introduces preclustering to handle correlated rounding errors. | |
| 2023 | Streaming | 1 + ε |
— | Dynamic, single-pass, semi-streaming; exponential runtime. Link TBD. | |
| 2024 | Streaming | 3 + ε |
— | Dynamic streams (insertions and deletions), single pass. | |
| 2024 | Parallel / MPC | 2.4 |
LP | LP-based; runs in O(m7.5) time. First result breaking the 3-approximation barrier in polylogarithmic parallel rounds. | |
| 2024 | Offline | 1.437 |
LP | LP-based rounding; integrality gap of 4/3. Significant advance in offline approximability. | |
| 2024 | Offline | 2 − 2/13 + ε |
— | Local-search based; no LP required. Breaks the 2-approximation barrier combinatorially. | |
| 2024 | Streaming | 1.847 |
— | Insertion-only streams. Best known approximation for streaming CC to date. | |
| 2025 | Streaming Learning-Aug. | min{2.06β, 3} + ε |
LP Pivot | Two variants: insertion-only and dynamic, both single-pass. Uses ML-predicted pairwise distances (β = prediction quality). Achieves better-than-3 with good predictions; degrades gracefully to Pivot otherwise. ICLR 2025. |