Gravitational wave (GW) searches using pulsar timing arrays (PTAs) are assumed to be limited by the typical average observational cadence of 1/(2 weeks) for a single pulsar to GW frequencies ≲4 10⁻⁷ Hz. We show that this assumption is incorrect and that a PTA can detect signals with much higher frequencies, which are preserved in the data due to aliasing, by exploiting asynchronous observations from multiple pulsars. This allows an observation strategy that is scalable to future large-scale PTAs containing O(10³) pulsars, enabled by the Five-hundred meter Aperture Spherical Telescope and the Square Kilometer Array, without requiring a higher per-pulsar observation cadence. We show that higher frequency GW observations, reaching up to 4 10⁻⁴ Hz with an Square Kilometer Array-era PTA, have significant astrophysical implications, such as (i) a three orders of magnitude better constraint than current high-cadence observations on GW strain in the [10, 400] μHz band, and (ii) sensitive tests of the no-hair theorem in the mass range of supermassive black hole binaries using their inspiral, merger, and ringdown signals.

假设使用脉冲星定时阵列（PTA）进行的引力波（GW）搜索受到单个脉冲星至GW频率≲410 ^-7 Hz的典型平均观测节奏的限制（1/2周）。我们证明了这种假设是不正确的，而且PTA可以通过利用来自多个脉冲星的异步观测来检测具有更高频率的信号，这些信号由于混叠而保留在数据中。这允许观察策略可扩展到包含O（10 ³）脉冲星的未来大型PTA ，并由五百米孔径球面望远镜和平方千米阵列实现，而无需更高的每脉冲星观测节奏。我们显示了更高频率的GW观测，达到了4 10 ^-4赫兹与平方公里阵时代PTA，具有显著天体物理影响，例如（i）大小更好约束的三个数量比在[10，400]上GW应变电流高韵律观测μ Hz频带，和（ii ）使用其吸气，合并和振铃信号对超质量黑洞双星质量范围内的无毛定理进行敏感测试。