Supergroup Structure of Jackiw-Teitelboim Supergravity

We develop the gauge theory formulation of $\mathcal{N}=1$ Jackiw-Teitelboim supergravity in terms of the underlying $\text{OSp}(1|2, \mathbb{R})$ supergroup, focusing on boundary dynamics and the exact structure of gravitational amplitudes. We prove that the BF description reduces to a super-Schwarzian quantum mechanics on the holographic boundary, where boundary-anchored Wilson lines map to bilocal operators in the super-Schwarzian theory. A classification of defects in terms of monodromies of $\text{OSp}(1|2, \mathbb{R})$ is carried out and interpreted in terms of character insertions in the bulk. From a mathematical perspective, we construct the principal series representations of $\text{OSp}(1|2, \mathbb{R})$ and show that whereas the corresponding Plancherel measure does not match the density of states of $\mathcal{N}=1$ JT supergravity, a restriction to the positive subsemigroup $\text{OSp}^+(1|2, \mathbb{R})$ yields the correct density of states, mirroring the analogous results for bosonic JT gravity. We illustrate these results with several gravitational applications, in particular computing the late-time complexity growth in JT supergravity.Comment: 54 pages + extensive appendices, v2: fixed typos and added reference

Electrical Tuning of Single Nitrogen-Vacancy Center Optical Transitions Enhanced by Photoinduced Fields

We demonstrate precise control over the zero-phonon optical transition energies of individual nitrogen-vacancy (NV) centers in diamond by applying multiaxis electric fields, via the dc Stark effect. The Stark shifts display surprising asymmetries that we attribute to an enhancement and rectification of the local electric field by photoionized charge traps in the diamond. Using this effect, we tune the excited-state orbitals of strained NV centers to degeneracy and vary the resulting degenerate optical transition frequency by >10 GHz, a scale comparable to the inhomogeneous frequency distribution. This technique will facilitate the integration of NV-center spins within photonic networks.Comment: 10 pages, 6 figure

SUSY Simplified Models at 14, 33, and 100 TeV Proton Colliders

Results are presented for a variety of SUSY Simplified Models at the 14 TeV LHC as well as a 33 and 100 TeV proton collider. Our focus is on models whose signals are driven by colored production. We present projections of the upper limit and discovery reach in the gluino-neutralino (for both light and heavy flavor decays), squark-neutralino, and gluino-squark Simplified Model planes. Depending on the model a jets + MET, mono-jet, or same-sign di-lepton search is applied. The impact of pileup is explored. This study utilizes the Snowmass backgrounds and combined detector. Assuming 3000 fb^{-1} of integrated luminosity, a gluino that decays to light flavor quarks can be discovered below 2.3 TeV at the 14 TeV LHC and below 11 TeV at a 100 TeV machine.Comment: 81 pages, 55 figures; v2 journal versio

Lightweight Heat Pipes Made from Magnesium

Magnesium has shown promise as a lighter-weight alternative to the aluminum alloys now used to make the main structural components of axially grooved heat pipes that contain ammonia as the working fluid. Magnesium heat-pipe structures can be fabricated by conventional processes that include extrusion, machining, welding, and bending. The thermal performances of magnesium heat pipes are the same as those of equal-sized aluminum heat pipes. However, by virtue of the lower mass density of magnesium, the magnesium heat pipes weigh 35 percent less. Conceived for use aboard spacecraft, magnesium heat pipes could also be attractive as heat-transfer devices in terrestrial applications in which minimization of weight is sought: examples include radio-communication equipment and laptop computers

Understanding MaaS: Past, Present and Future

Daily references to the changing landscape in the provision of passenger transport services is made in the transport literature, including grey material. Mobility as a Service (MaaS) is the acronym which appears to have caught the imagination of technology providers with promises of a new era of passenger transport whereby assets need not be owned and services can be bought at the point of need. It is the technological developments which have spearheaded the new understanding of MaaS.MaaS has evolved into a concept that integrates public and private transport services to provide one- stop access through a common interface. MaaS is at the centre of the popular view on future collaborative and connected mobility. For transport policy, MaaS is seen as a way to reduce car traffic, and its negative externalities, by enabling citizens to satisfy their mobility needs without having to own assets such as automobiles, either conventional or (in the future) self-driving. MaaS also opens new choices for non-car owning citizens who previously had limited transport options, making some of them socially excluded. Whilst definitions vary, the concept of MaaS has several dimensions: in the form of a smart app and in real-time, it provides mobility services using multimodal options, through a sophisticated journey planner that provides the user with multiple customised options and offers the opportunity for payment either at the point of use or with a pre-purchased mobility bundle. This single platform is envisaged to eventually be transferable around the world from city to city and region to region and also to remain pervasive to the user by working and monitoring the journey in real-time and providing options for recovery in the case of disruption, and with an aspiration to support public equity objectives.MaaS has also received considerable attention in recent years from decision-makers (for instance, the Finnish government has implemented new transport regulations intended to facilitate MaaS developments) and practitioners (examples of MaaS start-ups include MaaS Global in Finland, EC2B in Sweden and Moovel in Germany) as well as researchers (e.g., Hensher and Mulley (2019) Hensher, 2017; Jittrapirom, 2017; Sochor et al., 2016; Wong et al., 2019; Mulley, 2017). Still, the knowledge of MaaS is nascent, trials for the most part have not been thoroughly evaluated and the evidence for the mobility and societal benefits of MaaS have yet to be confirmed.The paper is structured as follows. The next section provides the literature context that underpins the part of the title of this paper relating to the ‘Past’. This is followed by a section detailing the present in terms of a current MaaS trial in Sydney, New South Wales, designed to provide another ‘data point’ in our current understanding of MaaS. The penultimate section looks to the future and the challenges ahead by identifying some key questions critical to the development of MaaS. The final section concludes

Polarized fluorescence depletion reports orientation distribution and rotational dynamics of muscle cross-bridges

The method of polarized fluorescence depletion (PFD) has been applied to enhance the resolution of orientational distributions and dynamics obtained from fluorescence polarization (FP) experiments on ordered systems, particularly in muscle fibers. Previous FP data from single fluorescent probes were limited to the 2nd- and 4th-rank order parameters, and , of the probe angular distribution (ß) relative to the fiber axis and , a coefficient describing the extent of rapid probe motions. We applied intense 12-µs polarized photoselection pulses to transiently populate the triplet state of rhodamine probes and measured the polarization of the ground-state depletion using a weak interrogation beam. PFD provides dynamic information describing the extent of motions on the time scale between the fluorescence lifetime (e.g., 4 ns) and the duration of the photoselection pulse and it potentially supplies information about the probe angular distribution corresponding to order parameters above rank 4. Gizzard myosin regulatory light chain (RLC) was labeled with the 6-isomer of iodoacetamidotetramethylrhodamine and exchanged into rabbit psoas muscle fibers. In active contraction, dynamic motions of the RLC on the PFD time scale were intermediate between those observed in relaxation and rigor. The results indicate that previously observed disorder of the light chain region in contraction can be ascribed principally to dynamic motions on the microsecond time scale

Homoepitaxial Growth of Single Crystal Diamond Membranes for Quantum Information Processing

Fabrication of devices designed to fully harness the unique properties of quantum mechanics through their coupling to quantum bits (qubits) is a prominent goal in the field of quantum information processing (QIP). Among various qubit candidates, nitrogen vacancy (NV) centers in diamond have recently emerged as an outstanding platform for room temperature QIP. However, formidable challenges still remain in processing diamond and in the fabrication of thin diamond membranes, which are necessary for planar photonic device engineering. Here we demonstrate epitaxial growth of single crystal diamond membranes using a conventional microwave chemical vapor deposition (CVD) technique. The grown membranes, only a few hundred nanometers thick, show bright luminescence, excellent Raman signature and good NV center electronic spin coherence times. Microdisk cavities fabricated from these membranes exhibit quality factors of up to 3000, overlapping with NV center emission. Our methodology offers a scalable approach for diamond device fabrication for photonics, spintronics, optomechanics and sensing applications.Engineering and Applied Science