Adverse Selection in an Insurance Market with Government-Guaranteed Subsistence Levels

We consider a competitive insurance market with adverse selection. Unlike the standard models, we assume that individuals receive the benefit of some type of potential government assistance that guarantees them a minimum level of wealth. For example, this assistance might be some type of government-sponsored relief program, or it might simply be some type of limited liability afforded via bankruptcy laws. Government assistance is calculated ex post of any insurance benefits. This alters the individuals’ demand for insurance coverage. In turn, this affects equilibria in various insurance models of markets with adverse selection.adverse selection, insurance, government relief

Anisotropy and Strong-Coupling Effects on the Collective Mode Spectrum of Chiral Superconductors: Application to Sr2_2RuO4_4

Recent theories of Sr$_2$RuO$_4$ based on the interplay of strong interactions, spin-orbit coupling and multi-band anisotropy predict chiral or helical ground states with strong anisotropy of the pairing states, with deep minima in the excitation gap, as well as strong phase anisotropy for the chiral ground state. We develop time-dependent mean field theory to calculate the Bosonic spectrum for the class of 2D chiral superconductors spanning $^3$He-A to chiral superconductors with strong anisotropy. Chiral superconductors support a pair of massive Bosonic excitations of the time-reversed pairs labeled by their parity under charge conjugation. These modes are degenerate for 2D $^3$He-A. Crystal field anisotropy lifts the degeneracy. Strong anisotropy also leads to low-lying Fermions, and thus to channels for the decay of the Bosonic modes. Selection rules and phase space considerations lead to large asymmetries in the lifetimes and hybridization of the Bosonic modes with the continuum of un-bound Fermion pairs. We also highlight results for the excitation of the Bosonic modes by microwave radiation that provide clear signatures of the Bosonic modes of an anisotropic chiral ground state.Comment: 11 pages with 8 figures. Presented as an invited talk as SCES14, Grenoble, France, July 201

Correlation function of dyonic strings

We investigate the two- and three-point correlation functions of the dyonic magnon and spike, which correspond to the solitonic string moving in the Poincare AdS and three-dimensional sphere. We show that the coupling between two dyonic magnons or spikes together with a marginal scalar operator in the string theory is exactly the same as one obtained by the RG analysis in the gauge theory.Comment: 15 pages, no figur

Rotating Black Hole Thermodynamics with a Particle Probe

The thermodynamics of Myers-Perry black holes in general dimensions are studied using a particle probe. When undergoing particle absorption, the changes of the entropy and irreducible mass are shown to be dependent on the particle radial momentum. The black hole thermodynamic behaviors are dependent on dimensionality for specific rotations. For a 4-dimensional Kerr black hole, its black hole properties are maintained for any particle absorption. 5-dimensional black holes can avoid a naked ring singularity by absorbing a particle in specific momenta ranges. Black holes over 6 dimensions become ultra-spinning black holes through a specific form of particle absorption. The microscopical changes are interpreted in limited cases of Myers-Perry black holes using Kerr/CFT correspondence. We systematically describe the black hole properties changed by particle absorption in all dimensions.Comment: 14 page

Stereotactic guidance for navigated percutaneous sacroiliac joint fusion.

Arthrodesis of the sacroiliac joint (SIJ) for surgical treatment of SIJ dysfunction has regained interest among spine specialists. Current techniques described in the literature most often utilize intraoperative fluoroscopy to aid in implant placement; however, image guidance for SIJ fusion may allow for minimally invasive percutaneous instrumentation with more precise implant placement. In the following cases, we performed percutaneous stereotactic navigated sacroiliac instrumentation using O-arm® multidimensional surgical imaging with StealthStation® navigation (Medtronic, Inc. Minneapolis, MN). Patients were positioned prone and an image-guidance reference frame was placed contralateral to the surgical site. O-arm® integrated with StealthStation® allowed immediate auto-registration. The skin incision was planned with an image-guidance probe. An image-guided awl, drill and tap were utilized to choose a starting point and trajectory. Threaded titanium cage(s) packed with autograft and/or allograft were then placed. O-arm® image-guidance allowed for implant placement in the SIJ with a small skin incision. However, we could not track the cage depth position with our current system, and in one patient, the SIJ cage had to be revised secondary to the anterior breach of sacrum

Proposal for reading out anyon qubits in non-abelian ν=12/5\nu = 12/5 quantum Hall state

To detect non-abelian statistics in the $\nu = 12/5$ quantum Hall state through interferometry, we apply an analysis similar to the ones proposed for the non-abelian $\nu = 5/2$ quantum Hall state. The result is that the amplitude of the Aharonov-Bohm oscillation of this interference is dependent on the internal states of quasiholes, but, in contrast to the $\nu = 5/2$ quantum Hall state, independent of the number of quasiholes. However, if the quasiholes are in a superposition state, it is necessary for the interferometer to have certain additional features to obtain the coefficients.Comment: 16 pages, 2 figures, Latex. Reference added, some errors corrected, some content changed, some changes in the abstrac

Structured Modeling with Hyperdag P Systems: Part A

P systems provide a computational model based on the structure and interaction of living cells. A P system consists of a hierarchical nesting of cell-like membranes, which can be visualized as a rooted tree. Although the P systems are computationally complete, many real world models, e.g., from socio-economic systems, databases, operating systems, distributed systems, seem to require more expressive power than provided by tree structures. Many such systems have a primary tree-like structure completed with shared or secondary communication channels. Modeling these as tree-based systems, while theoretically possible, is not very appealing, because it typically needs artificial extensions that introduce additional complexities, nonexistent in the originals. In this paper we propose and define a new model that combines structure and flexibility, called hyperdag P systems, in short, hP systems, which extend the definition of conventional P systems, by allowing dags, interpreted as hypergraphs, instead of trees, as models for the membrane structure. We investigate the relation between our hP systems and neural P systems. Despite using an apparently less powerful structure, i.e., a dag instead of a general graph, we argue that hP systems have essentially the same computational power as tissue and neural P systems. We argue that hP systems offer a structured approach to membrane-based modeling that is often closer to the behavior and underlying structure of the modeled objects. Additionally, we enable dynamical changes of the rewriting modes (e.g., to alternate between determinism and parallelism) and of the transfer modes (e.g., the switch between unicast or broadcast). In contrast, classical P systems, both tree and graph based P systems, seem to focus on a statical approach. We support our view with a simple but realistic example, inspired from computer networking, modeled as a hP system with a shared communication line (broadcast channel). In Part B of this paper we will explore this model further and support it with a more extensive set of examples

Mass inflation in f(R) gravity: A conjecture on the resolution of the mass inflation singularity

We study gravitational collapse of a charged black hole in f(R) gravity using double-null formalism. We require cosmological stability to f(R) models; we used the Starobinsky model and the R + (1/2)cR^2 model. Charged black holes in f(R) gravity can have a new type of singularity due to higher curvature corrections, the so-called f(R)-induced singularity, although it is highly model-dependent. As the advanced time increases, the internal structure will approach the Cauchy horizon, which may not be an inner apparent horizon. There is mass inflation as one approaches the Cauchy horizon and hence the Cauchy horizon may be a curvature singularity with nonzero area. However, the Ricci scalar is finite for an out-going null observer. This can be integrated as follows: Cosmologically stable higher curvature corrections of the Ricci scalar made it bounded even in the presence of mass inflation. Finally, we conjecture that if there is a general action including general higher curvature corrections with cosmological stability, then the corrections can make all curvature components finite even in the presence of mass inflation. This might help us to resolve the problem of inner horizon instability of regular black hole models.Comment: 31 pages, 15 figure

Holographic Meson Spectra in the Dense Medium with Chiral Condensate

We study two $1/N_c$ effects on the meson spectra by using the AdS/CFT correspondence where the $1/N_c$ corrections from the chiral condensate and the quark density are controlled by the gravitational backreaction of the massive scalar field and U(1) gauge field respectively. The dual geometries with zero and nonzero current quark masses are obtained numerically. We discuss meson spectra and binding energy of heavy quarkonium with the subleading corrections in the hard wall model.Comment: 16 pages, 4 figure

A Stroke or Not a Stroke? A Case of Chronic Hemiplegic Migraines

Hemiplegic migraine (HM) is a rare subtype of migraine with both familial and sporadic patterns. These migraines present episodically with reversible attacks of unilateral motor weakness. Patients may experience visual changes, sensory loss, impaired level of consciousness, ataxia, and speech changes. Symptoms can last from hours to days and can mimic acute stroke. The patient is a 45-year-old male with a past medical history of hypertension and possible cerebral vascular accident use who presents to the emergency department complaining of left extremity numbness and weakness. Neuroimaging showed no acute findings and CT angiogram showed no large vessel occlusion. Tenecteplase was administered and the patient was admitted to the neurologic intensive care unit due to high suspicion of stroke by neurology. On the following day, the patient reports a return to baseline without any neurologic deficits, ataxia, dysarthria, or paresthesia. The patient elaborates that similar episodes occur approximately 10 times a month that are usually milder in intensity. Preceding the episodes, he reports seeing “white speckles\u27\u27 and experiencing both phono and photosensitivity. The symptoms generally persist for about two hours and resolve spontaneously. Following current practice guidelines of management of HM, the patient was provided education on migraines. Atorvastatin, lisinopril, and propranolol were prescribed to control his hypertension that can decrease frequency of migraine and prevent ischemic strokes. Triptans are avoided in HM due to the risk of vasoconstriction. Lifestyle management including sleep hygiene, stress reduction, hydration, and avoiding triggers was discussed