theoretical-computer-science / Exact exponential algorithms; fine-grained complexity

Worst-case Subset Sum in time 2^((1/2 - c)n)

Theorem 1.1: a uniform randomized word-RAM algorithm decides Subset Sum with error at most 1/3 on every input and runs in worst-case time O(20.49n)O(2^{0.49n}) for every fixed polynomial bound on input bit length, the time bound holding on every random execution. The method combines isolation, a random prime modulus, a filtered Fourier checksum and alias extraction. It is not deterministic, it does not treat super-polynomial bit lengths, and it does not improve the space bound. The companion manuscript separately gives one-sided error, time poly(n)2n/2\mathrm{poly}(n)2^{n/2} and space O(2n/5)O(2^{n/5}).

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theoretical-computer-scienceOct 4, 2026Significance 46/100Registry: unreviewed

Worst-case Subset Sum in time 2^((1/2 - c)n)

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Theorem 1.1: a uniform randomized word-RAM algorithm decides Subset Sum with error at most 1/3 on every input and runs in worst-case time O(20.49n)O(2^{0.49n}) for every fixed polynomial bound on input bit length, the time bound holding on every random execution. The method combines isolation, a random prime modulus, a filtered Fourier checksum and alias extraction. It is not deterministic, it does not treat super-polynomi…

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Theorem 1.1: a uniform randomized word-RAM algorithm decides Subset Sum with error at most 1/3 on every input and runs in worst-case time O(20.49n)O(2^{0.49n}) for every fixed polynomial bound on input bit length, the time bound holding on every random execution. The method combines isolation, a random prime modulus, a filtered Fourier checksum and alias extraction. It is not deterministic, it does not treat super-polynomial bit lengths, and it does not improve the space bound. The companion manuscript separately gives one-sided error, time poly(n)2n/2\mathrm{poly}(n)2^{n/2} and space O(2n/5)O(2^{n/5}).

Theorem 1.1: a uniform randomized word-RAM algorithm decides Subset Sum with error at most 1/3 on every input and runs in worst-case time O(20.49n)O(2^{0.49n}) for every fixed polynomial bound on input bit length, the time bound holding on every random execution. The method combines isolation, a random prime modulus, a filtered Fourier checksum and alias extraction. It is not deterministic, it does not treat super-polynomial bit lengths, and it does not improve the space bound. The companion manuscript separately gives one-sided error, time poly(n)2n/2\mathrm{poly}(n)2^{n/2} and space O(2n/5)O(2^{n/5}).

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Worst-case Subset Sum in time 2^((1/2 - c)n) — Mathematical Frontier Network