Time-space lower bounds for breaking quantum cryptography
Researchers prove near-optimal time-space lower bounds for breaking quantum cryptography in the random oracle model.
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Stories tagged #lower-bounds
On the pseudorandomness of simple quantum processes
Simple local quantum processes can match unitary designs yet remain efficiently distinguishable from truly random unitaries.
A Nearly Quadratic Lower Bound for Linear Optimization over Convex Bodies in the Membership Oracle Model
Researchers prove nearly quadratic lower bounds for linear optimization over convex bodies in the membership oracle model.
New lower bounds for CDS and $f$-routing
New lower bounds tie robust CDS randomness to communication complexity and inner-product routing entanglement to sign rank.
Exponential Hardness of Off-Policy Evaluation under History-Dependent Logging
Researchers prove off-policy evaluation under history-dependent logging requires exponentially many episodes, resolving a hardness question for model-based POMDP evaluation.
Bridging the Gap Between Homogeneous and Heterogeneous Asynchronous Optimization Is Surprisingly Difficult
Lower bounds show heterogeneous asynchronous optimization cannot match homogeneous rates under standard similarity assumptions; strong interpolation plus local PL condition closes the gap.
Differential Privacy Meets Fixed Parameter Tractability: Algorithms and Lower Bounds
Theory paper combines differential privacy with fixed-parameter tractable encoders, improving approximation guarantees for combinatorial optimization and proving new lower bounds.
Silver Rate Is (Almost) Optimal for Gradient Descent Acceleration
New optimization theory paper proves near-optimal lower bounds for gradient descent with predetermined stepsizes, confirming silver-schedule optimality.