Ultralight Boson Dark Matter and Event Horizon Telescope Observations of M87

The initial data from the Event Horizon Telescope (EHT) on M87*, the supermassive black hole at the center of the M87 Galaxy, provide direct observational information on its mass, spin, and accretion disk properties. A combination of the EHT data and other constraints provides evidence that M87* has a mass similar to 6.5 x 10(9) M-circle dot. EHT also inferred the dimensionless spin parameter vertical bar a*vertical bar greater than or similar to 0.5 from jet properties; a separate recent analysis using only the light from near M87* as measured by the EHT Collaboration found vertical bar a*vertical bar=0.9 +/- 0.1. These determinations disfavor ultralight bosons of mass mu(b) is an element of (0.85; 4.6) x 10(-21) eV for spin-one bosons and mu(b) is an element of (2.9; 4.6) x 10(-21) eV for spin-zero bosons, within the range considered for fuzzy dark matter, invoked to explain dark matter distribution on approximately kiloparsec scales. Future observations of M87* could be expected to strengthen our conclusions.