Cosmological perturbation theory in Generalized Einstein-Aether models

We investigate the evolution of cosmological perturbations in models of dark energy described by a time-like unit normalized vector field specified by a general function $\mathcal{F}(\mathcal{K})$, so-called Generalized Einstein-Aether models. First we study the background dynamics of such models via a designer approach in an attempt to model this theory as dark energy. We find that only one specific form of this designer approach matches $\Lambda$CDM at background order and we also obtain a differential equation which $\mathcal{F}(\mathcal{K})$ must satisfy for general $w$CDM cosmologies. We also present the equations of state for perturbations in Generalized Einstein-Aether models, which completely parametrize these models at the level of linear perturbations. A generic feature of modified gravity models is that they introduce new degrees of freedom. By fully eliminating these we are able to express the gauge invariant entropy perturbation and the scalar, vector, and tensor anisotropic stresses in terms of the perturbed fluid variables and metric perturbations only. These can then be used to study the evolution of perturbations in the scalar, vector, and tensor sectors and we use these to evolve the Newtonian gravitational potentials.Comment: 26 pages, 4 figures, 3 tables, submitted to PR

Gravitational wave constraints on dark sector models

We explore the constraints on dark sector models imposed by the recent observation of coincident gravitational waves and gamma rays from a binary neutron star merger, GW170817. Rather than focusing on specific models as has been considered by other authors, we explore this in the context of the equation of state approach of which the specific models are special cases. After confirming the strong constraints found by others for Horndeski, Einstein-Aether and massive gravity models, we discuss how it is possible to construct models which might evade the constraints from GW170817 but still leading to cosmologically interesting modifications to gravity. Possible examples are ``miracle cancellations" such as in $f(R)$ models, nonlocal models and higher-order derivatives. The latter two rely on the dimensionless ratio of the wave number of the observed gravitational waves to the Hubble expansion rate being very large ($\sim10^{19}$) which is used to suppress modifications to the speed of gravitational waves.Comment: 10 page

Internal energy dissipation in Enceladus's ocean from tides and libration and the role of inertial waves

Enceladus is characterised by a south polar hot spot associated with a large outflow of heat, the source of which remains unclear. We compute the viscous dissipation resulting from tidal and libration forcing in the moon's subsurface ocean using the linearised Navier-Stokes equation in a 3-dimensional spherical model. We conclude that libration is the dominant cause of dissipation at the linear order, providing up to about 0.001 GW of heat to the ocean, which remains insufficient to explain the (about) 10 GW observed by Cassini. We also illustrate how resonances with inertial modes can significantly augment the dissipation. Our work is an extension to Rovira-Navarro et al. [2019] to include the effects of libration. The model developed here is readily applicable to the study of other moons and planets

Primer on adult patient satisfaction in perioperative settings.

The topic of patient satisfaction has gained increasing importance over the past decade. Due to the impact of patient satisfaction on health care quality, understanding factors that predict satisfaction is vital. The purpose of this review is to examine the literature and identify factors related to patient perioperative satisfaction as well as predictive variables that, if modified, can enhance satisfaction scores of patients undergoing surgery. Our review reports that patient satisfaction scores are affected by modifiable factors such as clinician-patient communication, information provision to patients, and operational function of a hospital. Non-modifiable factors affecting patient satisfaction scores include patient demographics such as gender, age, and education. In order to enhance patient perioperative satisfaction, we suggest that anesthesiologists and surgeons focus their efforts on enhancing their communication skills and providing information that is appropriately tailored to the understanding of their patients

Patterns on liquid surfaces: cnoidal waves, compactons and scaling

Localized patterns and nonlinear oscillation formation on the bounded free surface of an ideal incompressible liquid are analytically investigated . Cnoidal modes, solitons and compactons, as traveling non-axially symmetric shapes are discused. A finite-difference differential generalized Korteweg-de Vries equation is shown to describe the three-dimensional motion of the fluid surface and the limit of long and shallow channels one reobtains the well known KdV equation. A tentative expansion formula for the representation of the general solution of a nonlinear equation, for given initial condition is introduced on a graphical-algebraic basis. The model is useful in multilayer fluid dynamics, cluster formation, and nuclear physics since, up to an overall scale, these systems display liquid free surface behavior.Comment: 14 pages RevTex, 5 figures in p

Draft Genome Sequences of Two Vibrio parahaemolyticus Strains Associated with Gastroenteritis after Raw Seafood Ingestion in Colorado.

Vibrio parahaemolyticus is a Gram-negative pathogen associated with gastrointestinal and wound infections after exposure to raw seafood or contaminated waters. We report here the whole-genome sequences of two stool isolates (CDC-AM50933 and CDC-AM43539) from patients in Colorado presenting with gastroenteritis after ingesting raw seafood