4,232 research outputs found

    Tunable far infrared studies of molecular parameters in support of stratospheric measurements

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    Lab studies were made in support of far infrared spectroscopy of the stratosphere using the Tunable Far InfraRed (TuFIR) method of ultrahigh resolution spectroscopy and, more recently, spectroscopic and retrieval calculations performed in support of satellite-based atmospheric measurement programs: the Global Ozone Monitoring Experiment (GOME), and the SCanning Imaging Absorption spectroMeter for Atmospheric CHartographY (SCIAMACHY)

    The WAY theorem and the quantum resource theory of asymmetry

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    The WAY theorem establishes an important constraint that conservation laws impose on quantum mechanical measurements. We formulate the WAY theorem in the broader context of resource theories, where one is constrained to a subset of quantum mechanical operations described by a symmetry group. Establishing connections with the theory of quantum state discrimination we obtain optimal unitaries describing the measurement of arbitrary observables, explain how prior information can permit perfect measurements that circumvent the WAY constraint, and provide a framework that establishes a natural ordering on measurement apparatuses through a decomposition into asymmetry and charge subsystems.Comment: 11 pages, 3 figure

    Surface Tension at Finite Tempearture in the MIT Bag Model

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    At T=0 T = 0 the surface tension σ1/3 \sigma ^{1/3} in the MIT bag model for a single hadron is known to be negligible as compared to the bag pressure B1/4 B^{1/4}. We show that at finite temperature it has a substantial value of 50 - 70 MeV which also differ from hadron to hadron. We also find that the dynamics of the Quark-Gluon Plasma is such that the creation of hybrids (ssˉg)(s\bar{s}g) with massive quarks will predominate over the creation of (ssˉ) (s\bar{s}) mesons.Comment: Substantial changes in the revised version and a new author included, 13 pages in Latex and one figur

    The position profiles of order cancellations in an emerging stock market

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    Order submission and cancellation are two constituent actions of stock trading behaviors in order-driven markets. Order submission dynamics has been extensively studied for different markets, while order cancellation dynamics is less understood. There are two positions associated with a cancellation, that is, the price level in the limit-order book (LOB) and the position in the queue at each price level. We study the profiles of these two order cancellation positions through rebuilding the limit-order book using the order flow data of 23 liquid stocks traded on the Shenzhen Stock Exchange in the year 2003. We find that the profiles of relative price levels where cancellations occur obey a log-normal distribution. After normalizing the relative price level by removing the factor of order numbers stored at the price level, we find that the profiles exhibit a power-law scaling behavior on the right tails for both buy and sell orders. When focusing on the order cancellation positions in the queue at each price level, we find that the profiles increase rapidly in the front of the queue, and then fluctuate around a constant value till the end of the queue. These profiles are similar for different stocks. In addition, the profiles of cancellation positions can be fitted by an exponent function for both buy and sell orders. These two kinds of cancellation profiles seem universal for different stocks investigated and exhibit minor asymmetry between buy and sell orders. Our empirical findings shed new light on the order cancellation dynamics and pose constraints on the construction of order-driven stock market models.Comment: 17 pages, 6 figures and 6 table

    The discrimination of self from other as a component of empathy.

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    Despite the centrality of empathy in human social life, there is no widely agreed definition or characterization of the concept of empathy. A common thread in many of the proposed definitions, however, is that empathy presupposes the discrimination of self and other on the grounds that, to empathize with another individual, the mental state of the target individual must first be distinguished from the empathizer's own mental state. The purpose of this study is to investigate this proposal empirically. We employed a paradigm in which participants rated the emotional valence and degree of arousal of 93 facial expressions of mental states. We asked participants to infer the mental state represented by each facial expression (the Other condition) as well as to describe the effect of the expression on their own mental state (the Self condition). An absolute difference score between the Other and the Self conditions was used as an index of a capacity for self-other discrimination. Empathy was measured using the Interpersonal Reactivity Index. Results show that individuals high in trait empathy discriminate between self and other to a significantly greater degree when judging mental states than individuals low in trait empathy. This suggests that the capacity for self-other discrimination may be a component of the capacity for empathy and that future investigations of the concept of empathy ought to retain it. (PsycInfo Database Record (c) 2022 APA, all rights reserved)

    Spitzer Observations of NGC 1333: A Study of Structure and Evolution in a Nearby Embedded Cluster

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    We present a comprehensive analysis of structure in the young, embedded cluster, NGC 1333 using members identified with Spitzer and 2MASS photometry based on their IR-excess emission. In total, 137 members are identified in this way, composed of 39 protostars and 98 more evolved pre-main sequence stars with disks. Of the latter class, four are transition/debris disk candidates. The fraction of exposed pre-main sequence stars with disks is 83% +/- 11%, showing that there is a measurable diskless pre-main sequence population. The sources in each of the Class I and Class II evolutionary states are shown to have very different spatial distributions relative to the distribution of the dense gas in their natal cloud. However, the distribution of nearest neighbor spacings among these two groups of sources are found to be quite similar, with a strong peak at spacings of 0.045 pc. Radial and azimuthal density profiles and surface density maps computed from the identified YSOs show that NGC 1333 is elongated and not strongly centrally concentrated, confirming previous claims in the literature. We interpret these new results as signs of a low velocity dispersion, extremely young cluster that is not in virial equilibrium.Comment: 59 pages, 20 figures, accepted to ApJ, verion with full resolution figures available at http://www.cfa.harvard.edu/~rgutermuth/preprints/gutermuth_ngc1333.pdf . Updated to fix astro-ph figure garblin

    Effects of nuclear re-interactions in quasi-elastic neutrino-nucleus scattering

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    The effects of nuclear re-interactions in the quasi-elastic neutrino-nucleus scattering are investigated with a phenomenological model. We found that the nuclear responses are lowered and their maxima are shifted towards higher excitation energies. This is reflected on the total neutrino-nucleus cross section in a general reduction of about 15% for neutrino energies above 300 MeV.Comment: 15 pages, 5 figures. Submitted to AstroParticle Physic

    The pion-three-nucleon problem with two-cluster connected-kernel equations

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    It is found that the coupled piNNN-NNN system breaks into fragments in a nontrivial way. Assuming the particles as distinguishable, there are indeed four modes of fragmentation into two clusters, while in the standard three-body problem there are three possible two-cluster partitions and conversely the four-body problem has seven different possibilities. It is shown how to formulate the pion-three-nucleon collision problem through the integral-equation approach by taking into account the proper fragmentation of the system. The final result does not depend on the assumption of separability of the two-body t-matrices. Then, the quasiparticle method a' la Grassberger-Sandhas is applied and effective two-cluster connected-kernel equations are obtained. The corresponding bound-state problem is also formulated, and the resulting homogeneous equation provides a new approach which generalizes the commonly used techniques to describe the three-nucleon bound-state problem, where the meson degrees of freedom are usually suppressed.Comment: 20 pages, REVTeX, with 3 COLOR figures (PostScript

    Branch Rings, Thinned Rings, Tree Enveloping Rings

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    We develop the theory of ``branch algebras'', which are infinite-dimensional associative algebras that are isomorphic, up to taking subrings of finite codimension, to a matrix ring over themselves. The main examples come from groups acting on trees. In particular, for every field k we construct a k-algebra K which (1) is finitely generated and infinite-dimensional, but has only finite-dimensional quotients; (2) has a subalgebra of finite codimension, isomorphic to M2(K)M_2(K); (3) is prime; (4) has quadratic growth, and therefore Gelfand-Kirillov dimension 2; (5) is recursively presented; (6) satisfies no identity; (7) contains a transcendental, invertible element; (8) is semiprimitive if k has characteristic 2\neq2; (9) is graded if k has characteristic 2; (10) is primitive if k is a non-algebraic extension of GF(2); (11) is graded nil and Jacobson radical if k is an algebraic extension of GF(2).Comment: 35 pages; small changes wrt previous versio
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