Acceleration by stepsize hedging: Silver Stepsize Schedule for smooth convex optimization
We provide a concise, self-contained proof that the Silver Stepsize Schedule proposed in our companion paper directly applies to smooth (non-strongly) convex optimization. Specifically, we show that with these stepsizes, gradient descent computes an ε -minimizer in O ( ε - log ρ 2 ) = O ( ε - 0.7864...
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Format: | Article |
Language: | English |
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Springer Berlin Heidelberg
2024
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Online Access: | https://hdl.handle.net/1721.1/157702 |
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author | Altschuler, Jason M. Parrilo, Pablo A. |
author2 | Massachusetts Institute of Technology. Laboratory for Information and Decision Systems |
author_facet | Massachusetts Institute of Technology. Laboratory for Information and Decision Systems Altschuler, Jason M. Parrilo, Pablo A. |
author_sort | Altschuler, Jason M. |
collection | MIT |
description | We provide a concise, self-contained proof that the Silver Stepsize Schedule proposed in our companion paper directly applies to smooth (non-strongly) convex optimization. Specifically, we show that with these stepsizes, gradient descent computes an ε -minimizer in O ( ε - log ρ 2 ) = O ( ε - 0.7864 ) iterations, where ρ = 1 + 2 is the silver ratio. This is intermediate between the textbook unaccelerated rate O ( ε - 1 ) and the accelerated rate O ( ε - 1 / 2 ) due to Nesterov in 1983. The Silver Stepsize Schedule is a simple explicit fractal: the i-th stepsize is 1 + ρ ν ( i ) - 1 where ν ( i ) is the 2-adic valuation of i. The design and analysis are conceptually identical to the strongly convex setting in our companion paper, but simplify remarkably in this specific setting. |
first_indexed | 2025-02-19T04:19:03Z |
format | Article |
id | mit-1721.1/157702 |
institution | Massachusetts Institute of Technology |
language | English |
last_indexed | 2025-02-19T04:19:03Z |
publishDate | 2024 |
publisher | Springer Berlin Heidelberg |
record_format | dspace |
spelling | mit-1721.1/1577022024-12-23T05:07:35Z Acceleration by stepsize hedging: Silver Stepsize Schedule for smooth convex optimization Altschuler, Jason M. Parrilo, Pablo A. Massachusetts Institute of Technology. Laboratory for Information and Decision Systems We provide a concise, self-contained proof that the Silver Stepsize Schedule proposed in our companion paper directly applies to smooth (non-strongly) convex optimization. Specifically, we show that with these stepsizes, gradient descent computes an ε -minimizer in O ( ε - log ρ 2 ) = O ( ε - 0.7864 ) iterations, where ρ = 1 + 2 is the silver ratio. This is intermediate between the textbook unaccelerated rate O ( ε - 1 ) and the accelerated rate O ( ε - 1 / 2 ) due to Nesterov in 1983. The Silver Stepsize Schedule is a simple explicit fractal: the i-th stepsize is 1 + ρ ν ( i ) - 1 where ν ( i ) is the 2-adic valuation of i. The design and analysis are conceptually identical to the strongly convex setting in our companion paper, but simplify remarkably in this specific setting. 2024-12-02T18:51:34Z 2024-12-02T18:51:34Z 2024-11-25 2024-12-01T04:16:27Z Article http://purl.org/eprint/type/JournalArticle https://hdl.handle.net/1721.1/157702 Altschuler, J.M., Parrilo, P.A. Acceleration by stepsize hedging: Silver Stepsize Schedule for smooth convex optimization. Math. Program. (2024). PUBLISHER_CC en https://doi.org/10.1007/s10107-024-02164-2 Mathematical Programming Creative Commons Attribution https://creativecommons.org/licenses/by/4.0/ The Author(s) application/pdf Springer Berlin Heidelberg Springer Berlin Heidelberg |
spellingShingle | Altschuler, Jason M. Parrilo, Pablo A. Acceleration by stepsize hedging: Silver Stepsize Schedule for smooth convex optimization |
title | Acceleration by stepsize hedging: Silver Stepsize Schedule for smooth convex optimization |
title_full | Acceleration by stepsize hedging: Silver Stepsize Schedule for smooth convex optimization |
title_fullStr | Acceleration by stepsize hedging: Silver Stepsize Schedule for smooth convex optimization |
title_full_unstemmed | Acceleration by stepsize hedging: Silver Stepsize Schedule for smooth convex optimization |
title_short | Acceleration by stepsize hedging: Silver Stepsize Schedule for smooth convex optimization |
title_sort | acceleration by stepsize hedging silver stepsize schedule for smooth convex optimization |
url | https://hdl.handle.net/1721.1/157702 |
work_keys_str_mv | AT altschulerjasonm accelerationbystepsizehedgingsilverstepsizescheduleforsmoothconvexoptimization AT parrilopabloa accelerationbystepsizehedgingsilverstepsizescheduleforsmoothconvexoptimization |