PARAMETER ESTIMATION IN MULTIRESPONSE MODELS

This article identifies a new Old English poetic motif, ‘The Departure of the Hero in a Ship’, and discusses the implications of its presence in Beowulf, the signed poems of Cynewulf and Andreas, a group of texts already linked by shared lexis, imagery and themes. It argues that the Beowulf-poet used this motif to frame his work, foregrounding the question of royal succession. Cynewulf and the Andreas-poet then adapted this Beowulfian motif in a knowing and allusive manner for a new purpose: to glorify the church and to condemn its enemies. Investigation of this motif provides further evidence for the intertextuality of these works

Picoradian deflection measurement with an interferometric quasi-autocollimator using weak value amplification

We present an "interferometric quasi-autocollimator" that employs weak value amplification to measure angular deflections of a target mirror. The device has been designed to be insensitive to all translations of the target. We present a conceptual explanation of the amplification effect used by the device. An implementation of the device demonstrates sensitivities better than 10 picoradians per root hertz between 10 and 200 hertz.Comment: To be published in Optics Letter

Standard and Null Weak Values

Weak value (WV) is a quantum mechanical measurement protocol, proposed by Aharonov, Albert, and Vaidman. It consists of a weak measurement, which is weighed in, conditional on the outcome of a later, strong measurement. Here we define another two-step measurement protocol, null weak value (NVW), and point out its advantages as compared to WV. We present two alternative derivations of NWVs and compare them to the corresponding derivations of WVs.Comment: 11 pages, 2 figures. To appear in Quantum Theory: A Two-Time Success Story: Yakir Aharonov Festschrif

Weak Energy: Form and Function

The equation of motion for a time-independent weak value of a quantum mechanical observable contains a complex valued energy factor - the weak energy of evolution. This quantity is defined by the dynamics of the pre-selected and post-selected states which specify the observable's weak value. It is shown that this energy: (i) is manifested as dynamical and geometric phases that govern the evolution of the weak value during the measurement process; (ii) satisfies the Euler-Lagrange equations when expressed in terms of Pancharatnam (P) phase and Fubini-Study (FS) metric distance; (iii) provides for a PFS stationary action principle for quantum state evolution; (iv) time translates correlation amplitudes; (v) generalizes the temporal persistence of state normalization; and (vi) obeys a time-energy uncertainty relation. A similar complex valued quantity - the pointed weak energy of an evolving state - is also defined and several of its properties in PFS-coordinates are discussed. It is shown that the imaginary part of the pointed weak energy governs the state's survival probability and its real part is - to within a sign - the Mukunda-Simon geometric phase for arbitrary evolutions or the Aharonov-Anandan (AA) phase for cyclic evolutions. Pointed weak energy gauge transformations and the PFS 1-form are discussed and the relationship between the PFS 1-form and the AA connection 1-form is established.Comment: To appear in "Quantum Theory: A Two-Time Success Story"; Yakir Aharonov Festschrif

Free expansion of two-dimensional condensates with a vortex

We study the free expansion of a pancake-shaped Bose-condensed gas, which is initially trapped under harmonic confinement and containing a vortex at its centre. In the case of a radial expansion holding fixed the axial confinement we consider various models for the interactions, depending on the thickness of the condensate relative to the value of the scattering length. We are thus able to evaluate different scattering regimes ranging from quasi-three-dimensional (Q3D) to strictly two-dimensional (2D). We find that as the system goes from Q3D to 2D the expansion rate of the condensate increases whereas that of the vortex core decreases. In the Q3D scattering regime we also examine a fully free expansion in 3D and find oscillatory behaviour for the vortex core radius: an initial fast expansion of the vortex core is followed by a slowing down. Such a nonuniform expansion rate of the vortex core may be taken into account in designing new experiments.Comment: 10 pages, 4 figure

4-Meth­­oxy-4-methyl-6-phenyl-1,3-diazinane-2-thione

In the title pyrimidine derivative, C12H16N2OS, the tetra­hydro­pyrimidine ring adopts an envelope conformation with the C atom of the methyl­ene –CH2– group as the flap. In the crystal, N—H⋯O and N—H⋯S hydrogen bonds connect mol­ecules into undulating sheets perpendicular to the a axis

Quantum Optical Systems for the Implementation of Quantum Information Processing

We review the field of Quantum Optical Information from elementary considerations through to quantum computation schemes. We illustrate our discussion with descriptions of experimental demonstrations of key communication and processing tasks from the last decade and also look forward to the key results likely in the next decade. We examine both discrete (single photon) type processing as well as those which employ continuous variable manipulations. The mathematical formalism is kept to the minimum needed to understand the key theoretical and experimental results

(2E)-3-(6-Methoxynaphthalen-2-yl)-1-(pyridin-3-yl)prop-2-en-1-one and its cyclocondensation product with guanidine, (4RS)-2-amino-4-(6-methoxynaphthalen-2-yl)-6-(pyridin-3-yl)-3,4-dihydropyrimidine monohydrate: Two types of hydrogen-bonded sheet

The structures of a chalcone and of its cyclo­condensation product with guanidine are reported. In (2E)-3-(6-meth­oxy­naphthalen-2-yl)-1-(pyridin-3-yl)prop-2-en-1-one, C19H15NO2, (I), the planes of the pyridine and naphthalene units make dihedral angles with that of the central spacer unit of 23.61 (13) and 23.57 (15)°, respectively, and a dihedral angle of 47.24 (9)° with each other. The mol­ecules of (I) are linked into sheets by a combination of C-H...O and C-H...[pi](arene) hydrogen bonds. In the cyclo­condensation product (4RS)-2-amino-4-(6-meth­oxy­naphthalen-2-yl)-6-(pyri­din-3-yl)-3,4-dihydro­pyrimidine monohydrate, C20H18N4O·H2O, (II), the di­hydro­pyrimidine ring adopts a conformation best described as a shallow boat. The mol­ecular components are linked by two N-H...O hydrogen bonds, two O-H...N hydrogen bonds and one N-H...N hydrogen bond to form complex sheets, with the meth­oxy­naphthalene inter­digitated between inversion-related pairs of sheets