Thermodynamics of hairy black holes in Lovelock gravity

We perform a thorough study of the thermodynamic properties of a class of Lovelock black holes with conformal scalar hair arising from coupling of a real scalar field to the dimensionally extended Euler densities. We study the linearized equations of motion of the theory and describe constraints under which the theory is free from ghosts/tachyons. We then consider, within the context of black hole chemistry, the thermodynamics of the hairy black holes in the Gauss-Bonnet and cubic Lovelock theories. We clarify the connection between isolated critical points and thermodynamic singularities, finding a one parameter family of these critical points which occur for well-defined thermodynamic parameters. We also report on a number of novel results, including `virtual triple points' and the first example of a `$\lambda$-line'---a line of second order phase transitions---in black hole thermodynamics.Comment: 62 pages, 30 figures. Minor changes and typos corrected. Updated to match published versio

Performance, emissions, and physical characteristics of a rotating combustion aircraft engine, supplement A

Testing was conducted using the basic RC2-75 engine, to which several modifications were incorporated which were designed to reduce the hydrocarbon emissions and reduce the specific fuel consumption. The modifications included close-in surface gap spark plugs, increased compression ratio rotors, and provisions for utilizing either side or peripheral intake ports, or a combination of the two if required. The proposed EPA emissions requirements were met using the normal peripheral porting. The specific fuel economy demonstrated for the modified RC2-75 was 283 g/kW-hr at 75% power and 101 brake mean effective pressure (BMEP) and 272.5 g/kW-hr at 75% power and 111 BMEP. The latter would result from rating the engine for takeoff at 285 hp and 5500 rpm, instead of 6000 rpm

Modelling Clock Synchronization in the Chess gMAC WSN Protocol

We present a detailled timed automata model of the clock synchronization algorithm that is currently being used in a wireless sensor network (WSN) that has been developed by the Dutch company Chess. Using the Uppaal model checker, we establish that in certain cases a static, fully synchronized network may eventually become unsynchronized if the current algorithm is used, even in a setting with infinitesimal clock drifts

Entanglement Harvesting with Moving Mirrors

We study the phenomenon of entanglement extraction from the vacuum of a massless scalar field in $(1+1)$ dimensional spacetime in presence of a moving Dirichlet boundary condition, i.e. mirror spacetime, using two inertial Unruh-DeWitt detectors. We consider a variety of non-trivial trajectories for these accelerating mirrors and find (1) an entanglement inhibition phenomenon similar to that recently seen for black holes, as well as (2) trajectory-independent entanglement enhancement in some regimes. We show that the qualitative result obtained is the same for both linear and derivative couplings of the detector with the field.Comment: 18 pages, 9 figure

Unruh phenomena and thermalization for qudit detectors

We study Unruh phenomena for a qudit detector coupled to a quantized scalar field, comparing its response to that of a standard qubit-based Unruh-DeWitt detector. We show that there are limitations to the utility of the detailed balance condition as an indicator for Unruh thermality of higher-dimensional qudit detector models. This can be traced to the fact that a qudit has multiple possible transition channels between its energy levels, in contrast to the 2-level qubit model. We illustrate these limitations using two types of qutrit detector models based on the spin-1 representations of $SU(2)$ and the non-Hermitian generalization of the Pauli observables (the Heisenberg-Weyl operators).Comment: 10+5 pages, no figures; RevTeX4-

Prevalence of Cutibacterium acnes and Staph spp. in the lesions of acne vulgaris in Jakarta

Background: Acne vulgaris (AV) is a chronic skin disorder that is commonly seen in young adults. Recent studies have shown that bacteria other than Cuticubacterium acnes found in the skin microbiota also play vital roles in the pathogenesis of AV. Understanding the skin microbiota and its disruption in patients with AV is paramount in treating patients with AV. Methods: Samples were obtained from 36 subjects to evaluate the proportion of Cutibacterium acnes, Staphylococcus epidermidis, and Staphylococcus aureus in lesions of AV by means of bacterial culture. Results: There were 69 specimens collected from the 36 subjects with AV. The most abundant type of bacteria that was successfully isolated in the cultured AV lesions was Staphylococcus epidermidis(46.4%), followed by Cutibacterium acnes(14.5%), and Staphylococcus aureus(2.9%). Conclusion: Staphylococcus epidermidis,the major species of human skin flora, is the most abundant microorganism found in AV. The development of AV is not necessarily associated with the high proportion of Cutibacterium acnes. More pathogenic bacteria, such as Staphylococcus aureusis also not always found in the AV lesions. These findings may provide the basis for the clinicians to determine which types of antibiotics to prescribe for the treatment of AV