SYSTEM AND METHOD ENABLING SIMULTANEOUS INVESTIGATION OF SAMPLE WITH TWO BEAMS OF ELECTROMAGNETIC RADATION

Disclosed are System and method for characterizing a System consisting of a fluid Sample on a two sided Stage, utilizing data obtained by applying, from both sides thereof, beams of electromagnetic radiation to a fluid coated Surface in a containing cell Volume. The beams can have the same or different wavelength content and/or polarization State, and can be applied at the same or different magnitude angles-of-incidence, and a third typically unpolarized beam can be applied at a normal angle-of-incidence

SYSTEM AND METHOD ENABLING SIMULTANEOUS INVESTIGATION OF SAMPLE WITH TWO BEAMS OF ELECTROMAGNETIC RADIATION

Disclosed are system and method for a characterizing system consisting of a fluid sample on a two-sided stage, utilizing data obtained by applying, from both sides thereof, beams of electromagnetic radiation to a fluid coated surface in a containing cell volume. The beams can have the same or different wavelength content and/or polarization state and can be applied at the same or different magnitude angles-of-incidence, and a third typically unpolarized beam can be applied at a normal angle-of-incidence

Systematic effects from black hole-neutron star waveform model uncertainties on the neutron star equation of state

We identify various contributors of systematic effects in the measurement of the neutron star (NS) tidal deformability and quantify their magnitude for several types of neutron star - black hole (NSBH) binaries. Gravitational waves from NSBH mergers contain information about the components' masses and spins as well as the NS equation of state. Extracting this information requires comparison of the signal in noisy detector data with theoretical templates derived from some combination of post-Newtonian (PN) approximants, effective one-body (EOB) models and %analytic fits to numerical relativity (NR) simulations. The accuracy of these templates is limited by errors in the NR simulations, by the approximate nature of the PN/EOB waveforms, and by the hybridization procedure used to combine them. In this paper, we estimate the impact of these errors by constructing and comparing a set of PN-NR hybrid waveforms, for the first time with NR waveforms from two different codes, namely, SpEC and SACRA, for such systems. We then attempt to recover the parameters of the binary using two non-precessing template approximants. We find that systematic errors are too large for tidal effects to be accurately characterized for any realistic NS equation of state model. We conclude that NSBH waveform models must be significantly improved if they are to be useful for the extraction of NS equation of state information or even for distinguishing NSBH systems from binary black holes

Large-scale Evolution of Seconds-long Relativistic Jets from Black Hole-Neutron Star Mergers

We present the first numerical simulations that track the evolution of a black hole-neutron star (BH-NS) merger from pre-merger to $r\gtrsim10^{11}\,{\rm cm}$. The disk that forms after a merger of mass ratio $q=2$ ejects massive disk winds ($3-5\times10^{-2}\,M_\odot$). We introduce various post-merger magnetic configurations, and find that initial poloidal fields lead to jet launching shortly after the merger. The jet maintains a constant power due to the constancy of the large-scale BH magnetic flux, until the disk becomes magnetically arrested (MAD), where the jet power falls off as $L_j\sim t^{-2}$. All jets inevitably exhibit either excessive luminosity due to rapid MAD activation when accretion rate is high, or excessive duration due to delayed MAD activation, compared to typical short gamma-ray burst (sGRBs). This provides a natural explanation to long sGRBs such as GRB 211211A, but also raises a fundamental challenge to our understanding of jet formation in binary mergers. One possible implication being the necessity of higher binary mass ratios or moderate BH spins to launch typical sGRB jets. For post-merger disks with a toroidal magnetic field, dynamo processes delay jet launching such that the jets break out of the disk winds after several seconds. We show for the first time that sGRB jets with initial magnetization $\sigma_0>100$ retain significant magnetization ($\sigma\gg1$) at $r>10^{10}\,{\rm cm}$, emphasizing the importance of magnetic processes in the prompt emission. The jet-wind interaction leads to a power-law angular energy distribution by inflating an energetic cocoon, whose emission is studied in a companion paper.Comment: For movies of the simulations, see https://oregottlieb.com/bhns.htm

Chiral Modes at Exceptional Points in Exciton-Polariton Quantum Fluid

We demonstrate the generation of chiral modes-vortex flows with fixed handedness in exciton-polariton quantum fluids. The chiral modes arise in the vicinity of exceptional points (non-Hermitian spectral degeneracies) in an optically induced resonator for exciton polaritons. In particular, a vortex is generated by driving two dipole modes of the non-Hermitian ring resonator into degeneracy. Transition through the exceptional point in the space of the system's parameters is enabled by precise manipulation of real and imaginary parts of the closed-wall potential forming the resonator. As the system is driven to the vicinity of the exceptional point, we observe the formation of a vortex state with a fixed orbital angular momentum (topological charge). This method can be extended to generate higher-order orbital angular momentum states through coalescence of multiple non-Hermitian spectral degeneracies. Our Letter demonstrates the possibility of exploiting nontrivial and counterintuitive properties of waves near exceptional points in macroscopic quantum systems