Saved in:
Bibliographic Details
Main Authors: Zou, Yinan, Shisher, Md Kamran Chowdhury, Brinton, Christopher G., Tripathi, Vishrant
Format: Preprint
Published: 2026
Subjects:
Online Access:https://arxiv.org/abs/2602.18658
Tags: Add Tag
No Tags, Be the first to tag this record!
_version_ 1866908846208843776
author Zou, Yinan
Shisher, Md Kamran Chowdhury
Brinton, Christopher G.
Tripathi, Vishrant
author_facet Zou, Yinan
Shisher, Md Kamran Chowdhury
Brinton, Christopher G.
Tripathi, Vishrant
contents Parameter-efficient fine-tuning methods, such as LoRA, offer a practical way to adapt large vision and language models to client tasks. However, this becomes particularly challenging under task-level heterogeneity in federated deployments. In this regime, personalization requires balancing general knowledge with personalized knowledge, yet existing approaches largely rely on heuristic mixing rules and lack theoretical justification. Moreover, prior model merging approaches are also computation and communication intensive, making the process inefficient in federated settings. In this work, we propose Potara, a principled framework for federated personalization that constructs a personalized model for each client by merging two complementary models: (i) a federated model capturing general knowledge, and (ii) a local model capturing personalized knowledge. Through the construct of linear mode connectivity, we show that the expected task loss admits a variance trace upper bound, whose minimization yields closed-form optimal mixing weights that guarantee a tighter bound for the merged model than for either the federated or local model alone. Experiments on vision and language benchmarks show that Potara consistently improves personalization while reducing communication, leading to a strong performance-communication trade-off.
format Preprint
id arxiv_https___arxiv_org_abs_2602_18658
institution arXiv
publishDate 2026
record_format arxiv
spellingShingle Communication-Efficient Personalized Adaptation via Federated-Local Model Merging
Zou, Yinan
Shisher, Md Kamran Chowdhury
Brinton, Christopher G.
Tripathi, Vishrant
Machine Learning
Parameter-efficient fine-tuning methods, such as LoRA, offer a practical way to adapt large vision and language models to client tasks. However, this becomes particularly challenging under task-level heterogeneity in federated deployments. In this regime, personalization requires balancing general knowledge with personalized knowledge, yet existing approaches largely rely on heuristic mixing rules and lack theoretical justification. Moreover, prior model merging approaches are also computation and communication intensive, making the process inefficient in federated settings. In this work, we propose Potara, a principled framework for federated personalization that constructs a personalized model for each client by merging two complementary models: (i) a federated model capturing general knowledge, and (ii) a local model capturing personalized knowledge. Through the construct of linear mode connectivity, we show that the expected task loss admits a variance trace upper bound, whose minimization yields closed-form optimal mixing weights that guarantee a tighter bound for the merged model than for either the federated or local model alone. Experiments on vision and language benchmarks show that Potara consistently improves personalization while reducing communication, leading to a strong performance-communication trade-off.
title Communication-Efficient Personalized Adaptation via Federated-Local Model Merging
topic Machine Learning
url https://arxiv.org/abs/2602.18658