The Department of Physics at the University of Nevada, Reno invites applications for a Postdoctoral Scholar position (Derevianko group). The successful candidate will have the opportunity to contribute to one of two research areas:
(i) High-precision calculations in atomic parity violation, and/or
(ii) developing data analysis toolbox for novel, exotic physics, modality in multi-messenger astronomy with quantum sensors.
While previous experience in these specific areas is not mandatory, computational skills are essential for this role.
Feel free to reach out to Dr. Derevianko for further details.
In 1939, George Gamow published the book “Mr. Tompkins in Wonderland”, which tells a story about a world where fundamental constants have radically different values from those they have in the real world. Gamow's classic predates modern theories that generically promote fundamental constants to dynamic entities. Constants are no longer constant. Enter Mr. Tompkins world where the speed of light c is reduced to that of a speeding bicycle, i.e. ~10,000,000 times smaller than its usual value.
In Mr. Tompkins dream, the city does not need speed limits posted, as no matter how powerful a car is, it cannot move faster than the drastically different 25-mph speed of light. This is the effect of Einstein’s theory of relativity. No need for highway patrol!
Is this Mr. Tompkins world even possible from biology perspective? We find (see our paper) that if the speed of light were reduced 10-fold, the entire Mendeleev periodic table would shrink to elements from hydrogen to sulfur. The heavier elements become unstable due to electron-positron pair emission. In Mr. Tompkins alternative reality, where c is reduced to that of a speeding bicycle, even the hydrogen atom fails to exist.
We find several striking effects at the reduced speed of light. For example, Neon is no longer chemically inert and has the electronic structure of carbon. If the speed of light were ~10 times smaller, a neon-based life could have emerged.
Water molecule, which is bent in our world, unfolds and becomes linear at the reduced speed of light. As such, it no longer possesses dipole moment and would cease to serve as a universal solvent, a necessary condition for sustaining life.
Life, as we know it, can only happen in a certain range of values of fundamental constants (the anthropic principle). Life is fragile.
A clump of dark matter sweeping through Earth. If the speed of light inside the clump is reduced by ~a factor of ten, the consequences for life are catastrophic.
We extend the anthropic arguments to a regime of transient variations of fundamental constants. Such regime is characteristic of clumpy dark matter models where inside the clumps fundamental constants can reach values vastly different from their everyday values. The passage of such a macroscopic dark matter clump through Earth would make Earth uninhabitable. Requiring that such a clump did not encounter Earth over the past 4 billion years (the estimated age of lifeforms on our planet), we substantially improve constraints on a certain class of dark models.
Black hole mergers are known to emit gravitational waves and are not expected to generate anything else. However, describing the physics of merging black hole singularities requires the yet unknown theory of quantum gravity. Thus the mergers can be accompanied by the emission of yet undetected exotic fields. In our paper, just published in Nature Astronomy, we argue that atomic clock networks can be sensitive to exotic fields emitted by LIGO detected mergers. This opens an intriguing possibility for a novel, exotic physics, modality in multi-messenger astronomy.
Quantum sensor networks as exotic field telescopes for multi-messenger astronomy
Conner Dailey, Colin Bradley, Derek F. Jackson Kimball, Ibrahim A. Sulai, Szymon Pustelny, Arne Wickenbrock & Andrei Derevianko
Multi-messenger astronomy, the coordinated observation of different classes of signals that originate from the same astrophysical event, provides a wealth of information about astrophysical processes1. So far, multi-messenger astronomy has correlated signals from known fundamental forces and standard model particles like electromagnetic radiation, neutrinos and gravitational waves. Many of the open questions of modern physics suggest the existence of exotic fields with light quanta (with masses ≪1 eV c−2). Quantum sensor networks could be used to search for astrophysical signals that are predicted by theories beyond the standard model that address these questions. Here, we show that networks of precision quantum sensors that, by design, are shielded from or are insensitive to conventional standard model physics signals can be a powerful tool for multi-messenger astronomy. We consider the case in which high-energy astrophysical events produce intense bursts of exotic low-mass fields (ELFs), and we propose a novel model for the potential detection of an ELF signal on the basis of general assumptions. We estimate ELF signal amplitudes, delays, rates and distances of gravitational-wave sources to which global networks of atomic magnetometers and atomic clocks could be sensitive. We find that such precision quantum sensor networks can function as ELF telescopes to detect signals from sources that generate ELF bursts of sufficient intensity.
A black hole merger (left) emits a burst of exotic low-mass fields (ELFs) and gravitational waves. As the ELF burst propagates with the group velocity vg ≲ c to the detector (right), it lags behind the emitted gravitational waves, which propagate at c. Given that the more energetic ELF components propagate faster, the detected ELF wave packet exhibits a characteristic frequency chirp, depicted by the wave packet shown on the right.
The University of Nevada, Reno, USA invites applications for a full-time Postdoctoral Scholar position with the Department of Physics. The postdoctoral scholar will work in the group of Dr. A. Derevianko. The primary task will be to carry out next-generation calculations of atomic parity violation. Additional topics of interest include dark matter searches and atomic and nuclear clocks. Experience with relativistic atomic many-body theory is desired, but not required. Demonstrated experience in computational physics is required. Anticipated start date is September 1, 2019. Please apply by sending email to Dr. Derevianko ([email protected]).
Job Description: The University of Nevada, Reno invites applications for a full-time Postdoctoral Scholar position with the Department of Physics to work with the GPS.DM collaboration. The GPS.DM collaboration carries out a search for ultralight dark matter with GPS constellation atomic clock data.
The postdoctoral associate will be primarily responsible for mining archival GPS data and developing statistical analysis. Website of the collaboration: http://www.dereviankogroup.com/gps-dark-matter/ . Applications received by July 10, 2019 will be given full consideration, but the search will remain open until a suitable applicant is found.
Required Qualifications: Ph.D. in Physics or closely related field by the time of appointment.
Preferred Qualifications: Computational skills and demonstrated experience with statistical analysis.
Required Attachment(s): Attach the following documents to your application.
1) Resume/CV 2) Cover letter 3) You will be required to provide at least two reference letters to be sent by email to Professor Andrei Derevianko at [email protected] .
