We introduce a parametrized high-density equation of state (EOS) in order to systematize the study constraints placed by astrophysical observations on nature neutron-star matter. To obtain useful constraints, number parameters must be smaller than EOS-related properties measured, but large enough accurately approximate set candidate EOSs. find that EOS based piecewise polytropes with 3 free matches, about 4% rms error, an extensive EOSs at densities below central density...

view Abstract Citations (494) References (17) Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS Secular instability of rotating Newtonian stars. Friedman, J. L. ; Schutz, B. F. The effect gravitational radiation and viscosity on the stability self-gravitating fluids is analyzed. It found that all stars are unstable or marginally to radiation. criterion for against shown involve canonical energy in a frame, functional invariant under gauge transformations...

Perturbations of rotating relativistic stars can be classified by their behavior under parity. For axial perturbations (r-modes), initial data with negative canonical energy is found angular dependence eimϕ for all values m ≥ 2 and arbitrarily slow rotation. This implies instability (or marginal stability) such perfect fluids. low m-instability strikingly different from the to polar perturbations, which sets in first large m. The timescale appears, small velocity Ω, proportional a high power...

All three-manifolds are known to occur as Cauchy surfaces of asymptotically flat vacuum spacetimes and with positive-energy sources. We prove here the conjecture that general relativity does not allow an observer probe topology spacetime: Any topological structure collapses too quickly light traverse it. More precisely, in a globally hyperbolic, spacetime satisfying null energy condition, every causal curve from ${\mathit{scrI}}^{\mathrm{\ensuremath{-}}}$ ${\mathit{scrI}}^{+}$ is homotopic...

We report the results of a first study that uses numerical simulations to estimate accuracy with which one can use gravitational wave observations double neutron-star inspiral measure parameters equation state. The evolution and initial-data codes Shibata Ury\ifmmode \bar{u}\else \={u}\fi{} compute last several orbits merger neutron stars, matter described by parametrized Previous work suggested an effective cutoff frequency place constraints on find, however, greater is obtained measuring...

view Abstract Citations (238) References (21) Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS Lagrangian perturbation theory of nonrelativistic fluids. Friedman, J. L. ; Schutz, B. F. The reported investigation is concerned with fluid and the secular instability rotating Newtonian stars. A formalism developed for perturbations a stationary fluid, description introduced in terms displacement. class trivial displacements identified, an explicit form obtained...

Using an extended set of equations state and a multiple-group multiple-code collaborative effort to generate waveforms, we improve numerical-relativity-based data-analysis estimates the measurability matter effects in neutron-star binaries. We vary two parameters parameterized piecewise-polytropic equation (EOS) analyze EOS properties, via parameter {\Lambda} that characterizes quadrupole deformability isolated neutron star. find that, within accuracy simulations, departure waveform from...

view Abstract Citations (435) References (22) Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS Comparing Models of Rapidly Rotating Relativistic Stars Constructed by Two Numerical Methods Stergioulas, Nikolaos ; Friedman, John L. We present the first direct comparison codes based on two different numerical methods for constructing rapidly rotating relativistic stars. A code Komatsu-Eriguchi-Hachisu (KEH) method (Komatsu et al. 1989), written is compared to...

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The laws of physics might permit the existence, in real Universe, closed timelike curves (CTC's). Macroscopic CTC's be a semiclassical consequence Planck-scale, quantum gravitational, Lorentzian foam, if such foam exists. If are permitted, then (the with gravity classical and other fields quantized or classical) should augmented by principle self-consistency, which states that local solution to equations can occur Universe only it extended part global solution, one is well defined throughout...

view Abstract Citations (167) References (17) Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS Turning Point Method for Axisymmetric Stability of Rotating Relativistic Stars Friedman, John L. ; Ipser, James R. Sorkin, Rafael D. A turning-point method is used to obtain a simple criterion governing the secular stability uniformly rotating relativistic stars axisymmetric perturbations. In particular, along sequence neutron with fixed angular momentum and...

The late inspiral, merger, and ringdown of a black hole-neutron star (BHNS) system can provide information about the neutron-star equation state (EOS). Candidate EOSs be approximated by parametrized piecewise-polytropic EOS above nuclear density, matched to fixed low-density EOS; we report results from large set BHNS inspiral simulations that systematically vary two parameters. To within accuracy simulations, find that, apart mass, single physical parameter $\ensuremath{\Lambda}$, describing...

Information about the neutron-star equation of state is encoded in waveform a black hole-neutron star system through tidal interactions and possible disruption neutron star. During inspiral this information depends on deformability Lambda star, we find that best measured parameter during merger ringdown as well. We performed 134 simulations where systematically varied well mass ratio, mass, aligned spin hole. Using these have developed an analytic representation full inspiral-merger-ringdown...

THE literature contains many reports of patients with leukemia who have had pregnancies terminating successfully in the birth normal infants.1 , 2 Thus far, no child born a mother has been observed to same disease.3 4 The present report concerns an infant whom acute lymphocytic developed at nine months age. signs and symptoms beginning seventh month pregnancy, although diagnosis was not established until eight days post partum.Case ReportsCase 1. J.C.M. (S.U.I.H. 57–8059), 32-year-old...

All three-manifolds are known to occur as Cauchy surfaces of asymptotically flat vacuum spacetimes and with positive-energy sources.We prove here the conjecture that general relativity does not allow an observer probe topology spacetime: any topological structure collapses too quickly light traverse it.More precisely, in a globally hyperbolic, spacetime satisfying null energy condition, every causal curve from J ( -to + is homotopic topologically trivial - .(If Poincaré false, theorem...

Causality alone suffices to set a lower bound on the period of rotation relativistic stars as function their maximum observed mass. That is, by assuming one-parameter equation state (EOS) that satisfies vsound < c and allows with masses large largest neutron star mass, M, we find P(ms)>0.282+0.196(M/M-1.442). The limit does not assume EOS agrees known low-density form for ordinary matter, if one adds assumption, minimum is raised few percent: match at n = 0.1 fm-3, P(ms)>0.295 +...

New models of rotating neutron stars show that only a surprisingly narrow range possible equations state (EOS's) can simultaneously allow star with frequency as large 1968 Hz and spherical (nonrotating) mass 1.44${\mathrm{M}}_{\mathrm{\ensuremath{\bigodot}}}$. The baryon for the 1968-Hz exceed 1.5${\mathrm{M}}_{\mathrm{\ensuremath{\bigodot}}}$ 1.7${\mathrm{M}}_{\mathrm{\ensuremath{\bigodot}}}$, implying progenitor >1.7${\mathrm{M}}_{\mathrm{\ensuremath{\bigodot}}}$. Those EOS's allowed have,...

Almost none of the r-modes ordinarily found in rotating stars exist, if star and its perturbations obey same one-parameter equation state; relativistic with equations state have no pure at all, modes whose limit, for a zero angular velocity, is perturbation axial parity. Similarly (as we show here), this kind g-modes, spherical limit polar parity vanishing perturbed pressure density. Where these gone? In kind, g-modes form degenerate zero-frequency subspace. We find that rotation splits...

For a certain class of three-manifolds, the angular momentum an asymptotically flat quantum gravitational field can have half-integral values.Received 11 February 1980DOI:https://doi.org/10.1103/PhysRevLett.44.1100©1980 American Physical Society

In this, the first of two companion papers, we present a method for finding gravitational self-force in modified radiation gauge particle moving on geodesic Schwarzschild or Kerr spacetime. An extension an earlier result by Wald is used to show spin weight $\ifmmode\pm\else\textpm\fi{}2$ perturbed Weyl scalar (${\ensuremath{\psi}}_{0}$ ${\ensuremath{\psi}}_{4}$) determines metric perturbation outside up transformation and infinitesimal change mass angular momentum. A Hertz potential...

This is the first of two papers on computing self-force in a radiation gauge for particle mass $\mathfrak{m}$ moving circular, equatorial orbit about Kerr black hole. In extreme-mass-ratio inspiral (EMRI) framework, with mode-sum renormalization, we compute renormalized value quantity $H\ensuremath{\mathrel{:=}}\frac{1}{2}{h}_{\ensuremath{\alpha}\ensuremath{\beta}}{u}^{\ensuremath{\alpha}}{u}^{\ensuremath{\beta}}$, gauge-invariant under transformations generated by helically symmetric...