On the sum-of-squares degree of symmetric quadratic functions

We study how well functions over the boolean hypercube of the form f_k(x)=(lxl-k)(lxl-k-1) can be approximated by sums of squares of low-degree polynomials, obtaining good bounds for the case of approximation in l_{infinity}-norm as well as in l_1-norm. We describe three complexity-theoretic applica...

Full description

Bibliographic Details
Main Authors: de Wolf, Ronald, Yuen, Henry, Lee, Troy, Prakash, Anupam
Other Authors: School of Physical and Mathematical Sciences
Format: Journal Article
Language:English
Published: 2018
Subjects:
Online Access:https://hdl.handle.net/10356/90218
http://hdl.handle.net/10220/47238
_version_ 1811678926277181440
author de Wolf, Ronald
Yuen, Henry
Lee, Troy
Prakash, Anupam
author2 School of Physical and Mathematical Sciences
author_facet School of Physical and Mathematical Sciences
de Wolf, Ronald
Yuen, Henry
Lee, Troy
Prakash, Anupam
author_sort de Wolf, Ronald
collection NTU
description We study how well functions over the boolean hypercube of the form f_k(x)=(lxl-k)(lxl-k-1) can be approximated by sums of squares of low-degree polynomials, obtaining good bounds for the case of approximation in l_{infinity}-norm as well as in l_1-norm. We describe three complexity-theoretic applications: (1) a proof that the recent breakthrough lower bound of Lee, Raghavendra, and Steurer [Lee/Raghavendra/Steurer, STOC 2015] on the positive semidefinite extension complexity of the correlation and TSP polytopes cannot be improved further by showing better sum-of-squares degree lower bounds on l_1-approximation of f_k; (2) a proof that Grigoriev's lower bound on the degree of Positivstellensatz refutations for the knapsack problem is optimal, answering an open question from [Grigoriev, Comp. Compl. 2001]; (3) bounds on the query complexity of quantum algorithms whose expected output approximates such functions.
first_indexed 2024-10-01T03:01:01Z
format Journal Article
id ntu-10356/90218
institution Nanyang Technological University
language English
last_indexed 2024-10-01T03:01:01Z
publishDate 2018
record_format dspace
spelling ntu-10356/902182023-02-28T19:24:13Z On the sum-of-squares degree of symmetric quadratic functions de Wolf, Ronald Yuen, Henry Lee, Troy Prakash, Anupam School of Physical and Mathematical Sciences Sum-of-squares Degree Approximation Theory DRNTU::Science::Physics We study how well functions over the boolean hypercube of the form f_k(x)=(lxl-k)(lxl-k-1) can be approximated by sums of squares of low-degree polynomials, obtaining good bounds for the case of approximation in l_{infinity}-norm as well as in l_1-norm. We describe three complexity-theoretic applications: (1) a proof that the recent breakthrough lower bound of Lee, Raghavendra, and Steurer [Lee/Raghavendra/Steurer, STOC 2015] on the positive semidefinite extension complexity of the correlation and TSP polytopes cannot be improved further by showing better sum-of-squares degree lower bounds on l_1-approximation of f_k; (2) a proof that Grigoriev's lower bound on the degree of Positivstellensatz refutations for the knapsack problem is optimal, answering an open question from [Grigoriev, Comp. Compl. 2001]; (3) bounds on the query complexity of quantum algorithms whose expected output approximates such functions. NRF (Natl Research Foundation, S’pore) Published version 2018-12-27T04:51:15Z 2019-12-06T17:43:21Z 2018-12-27T04:51:15Z 2019-12-06T17:43:21Z 2016 Journal Article Lee, T., Prakash, A., de Wolf, R., & Yuen, H. (2016). On the sum-of-squares degree of symmetric quadratic functions. Leibniz International Proceedings in Informatics, 50, 17-. doi:10.4230/LIPIcs.CCC.2016.17 https://hdl.handle.net/10356/90218 http://hdl.handle.net/10220/47238 10.4230/LIPIcs.CCC.2016.17 en Leibniz International Proceedings in Informatics © 2016 The Author(s) (Leibniz International Proceedings in Informatics). Licensed under Creative Commons License CC-BY. 31 p. application/pdf
spellingShingle Sum-of-squares Degree
Approximation Theory
DRNTU::Science::Physics
de Wolf, Ronald
Yuen, Henry
Lee, Troy
Prakash, Anupam
On the sum-of-squares degree of symmetric quadratic functions
title On the sum-of-squares degree of symmetric quadratic functions
title_full On the sum-of-squares degree of symmetric quadratic functions
title_fullStr On the sum-of-squares degree of symmetric quadratic functions
title_full_unstemmed On the sum-of-squares degree of symmetric quadratic functions
title_short On the sum-of-squares degree of symmetric quadratic functions
title_sort on the sum of squares degree of symmetric quadratic functions
topic Sum-of-squares Degree
Approximation Theory
DRNTU::Science::Physics
url https://hdl.handle.net/10356/90218
http://hdl.handle.net/10220/47238
work_keys_str_mv AT dewolfronald onthesumofsquaresdegreeofsymmetricquadraticfunctions
AT yuenhenry onthesumofsquaresdegreeofsymmetricquadraticfunctions
AT leetroy onthesumofsquaresdegreeofsymmetricquadraticfunctions
AT prakashanupam onthesumofsquaresdegreeofsymmetricquadraticfunctions