Undergrad New table-top gravitational-wave detector proposed

[Zeke137]

TL;DR

A group at Northwestern University is starting work on a gravitational-wave detector small enough to fit on a table-top and which uses levitated sensors to detect gravitational waves at frequencies higher than those detectable by current detectors.

The group is led by Andrew Geraci, an associate professor of physics and astronomy in Northwestern’s Weinberg College of Arts and Sciences .

It would appear that the sensors employ optically-trapped microspheres or microdiscs, the positions of which can be measured to microns or better as these images from Northwestern suggest:

Fig. 1 - High frequency gravitational wave detection with levitated sensors

Fig. 2 - Testing gravity at micron distances with optically trapped microspheres Just found this paper on arxiv by Geraci and Arvanitaki from 2013, which lays the groundwork for the proposed detector: Detecting high-frequency gravitational waves with optically-levitated sensors . The paper suggests that the detector would have

...improved sensitivity in the frequency range of 50−300 kHz that does not rely on a shot-noise limited displacement measurement of test mass mirrors, but rather depends on a precision force measurement on the resonant harmonically trapped sensor.

If somebody knows more about this project, I'm sure the folks here at PF would like to know more.

 

[websterling]

Geraci and his group are proponents of table-top experiments for quite a few different phenomena. This was just published at PRL-

Searching for Ultralight Dark Matter with Optical Cavities
We discuss the use of optical cavities as tools to search for dark matter (DM) composed of virialized ultralight fields (VULFs). Such fields could lead to oscillating fundamental constants, resulting in oscillations of the length of rigid bodies. We propose searching for these effects via differential strain measurement of rigid and suspended-mirror cavities. We estimate that more than 2 orders of magnitude of unexplored phase space for VULF DM couplings can be probed at VULF Compton frequencies in the audible range of 0.1–10 kHz.

Geraci Research Group

 

[Zeke137]

Geraci and his group are proponents of table-top experiments for quite a few different phenomena. This was just published at PRL-

Searching for Ultralight Dark Matter with Optical Cavities
We discuss the use of optical cavities as tools to search for dark matter (DM) composed of virialized ultralight fields (VULFs). Such fields could lead to oscillating fundamental constants, resulting in oscillations of the length of rigid bodies. We propose searching for these effects via differential strain measurement of rigid and suspended-mirror cavities. We estimate that more than 2 orders of magnitude of unexplored phase space for VULF DM couplings can be probed at VULF Compton frequencies in the audible range of 0.1–10 kHz.

Geraci Research Group

Thanks for the links - the paper you link to is, unfortunately for those like myself who have no access to such things, behind a paywall. Luckily, though, arxiv has a copy for free at https://arxiv.org/pdf/1808.00540.pdf - it's the same paper which, incidentally, was originally received by PRL in August 2018, but does not feature the revision from February 2019 as published by PRL. I would assume, however, that the two versions give essentially the same discussion of their experimental setup.

It's an interesting paper, and proposes a setup rather different from that proposed for their gravitational-wave detector.