Stephen Hawking

Stephen Hawking was an inspiration, both scientifically and personally.  He will be remembered and missed.  I had the pleasure of meeting Stephen last July.  It seemed to me that even then, he enjoyed his life more than many people who were vastly healthier than he.

Thermal Hawking radiation stimulated by vacuum fluctuations

We observe a thermal distribution of Hawking radiation, stimulated by quantum vacuum fluctuations, emanating from an analogue black hole.  This confirms Hawking’s prediction regarding black hole thermodynamics.  The thermal distribution is accompanied by correlations between the Hawking particles outside the black hole and the partner particles inside.  We find that the high energy pairs of Hawking and partner particles are entangled, while the low energy pairs are not.  The entanglement verifies an important element in the disussion of information loss in a black hole.  The observation of Hawking radiation verifies Hawking’s calculation, which is viewed as a milestone in the quest for quantum gravity.

Measuring the entanglement of Hawking radiation by density measurements

We theoretically study the entanglement of Hawking radiation emitted by an analogue black hole. We find that this entanglement can be measured by the experimentally accessible density-density correlation function, vastly simplifying the measurement. …