8,182 research outputs found
Hydrodynamics in 1+1 dimensions with gravitational anomalies
The constraints imposed on hydrodynamics by the structure of gauge and
gravitational anomalies are studied in two dimensions. By explicit integration
of the consistent gravitational anomaly, we derive the equilibrium partition
function at second derivative order. This partition function is then used to
compute the parity-violating part of the covariant energy-momentum tensor and
the transport coefficients.Comment: 9 pages, JHEP format.v2; added comments and references, matching
published versio
The colored Hanbury Brown--Twiss effect
The Hanbury Brown--Twiss effect is one of the celebrated phenomenologies of
modern physics that accommodates equally well classical (interferences of
waves) and quantum (correlations between indistinguishable particles)
interpretations. The effect was discovered in the late thirties with a basic
observation of Hanbury Brown that radio-pulses from two distinct antennas
generate signals on the oscilloscope that wiggle similarly to the naked eye.
When Hanbury Brown and his mathematician colleague Twiss took the obvious step
to propose bringing the effect in the optical range, they met with considerable
opposition as single-photon interferences were deemed impossible. The Hanbury
Brown--Twiss effect is nowadays universally accepted and, being so fundamental,
embodies many subtleties of our understanding of the wave/particle dual nature
of light. Thanks to a novel experimental technique, we report here a
generalized version of the Hanbury Brown--Twiss effect to include the frequency
of the detected light, or, from the particle point of view, the energy of the
detected photons. In addition to the known tendencies of indistinguishable
photons to arrive together on the detector, we find that photons of different
colors present the opposite characteristic of avoiding each others. We
postulate that fermions can be similarly brought to exhibit positive
(boson-like) correlations by frequency filtering.Comment: 18 pages, includes supplementary material of the derivation
The host of the Type I SLSN 2017egm: A young, sub-solar metallicity environment in a massive spiral galaxy
Here we present an integral-field study of the massive, high-metallicity
spiral NGC 3191, the host of SN 2017egm, the closest SLSN Type I to date. We
use data from PMAS/CAHA and the public MaNGA survey to shed light on the
properties of the SLSN site and the origin of star-formation in this
non-starburst spiral galaxy. We map the physical properties different
\ion{H}{II} regions throughout the galaxy and characterize their stellar
populations using the STARLIGHT fitting code. Kinematical information allows to
study a possible interaction with its neighbouring galaxy as the origin of
recent star formation activity which could have caused the SLSN. NGC 3191 shows
intense star-formation in the western part with three large SF regions of low
metallicity. The central regions of the host have a higher metallicity, lower
specific star-formation rate and lower ionization. Modeling the stellar
populations gives a different picture: The SLSN region has two dominant stellar
populations with different ages, the youngest one with an age of 2-10 Myr and
lower metallicity, likely the population from which the SN progenitor
originated. Emission line kinematics of NGC 3191 show indications of
interaction with its neighbour MCG+08-19-017 at 45 kpc, which might be
responsible for the recent starburst. In fact, this galaxy pair has in total
hosted 4 SNe, 1988B (Type Ia), SN 2003ds (Type Ic in MCG+08-19-017), PTF10bgl
(SLSN-Type II) and 2017egm, underlying the enhanced SF in both galaxies due to
interaction. Our study shows that one has to be careful interpreting global
host and even gas properties without looking at the stellar population history
of the region. SLSNe seem to still be consistent with massive stars ( 20
M) requiring low () metallicity and those environments
can also occur in massive, late-type galaxies but not necessarily starbursts.Comment: Accepted for publication in A&A, 13 pages, 11 figures, 7 tables.
Abstract has been reduced to match arXiv form requirement
Fractal Dimension and Localization of DNA Knots
The scaling properties of DNA knots of different complexities were studied by
atomic force microscope. Following two different protocols DNA knots are
adsorbed onto a mica surface in regimes of (i) strong binding, that induces a
kinetic trapping of the three-dimensional (3D) configuration, and of (ii) weak
binding, that permits (partial) relaxation on the surface. In (i) the gyration
radius of the adsorbed DNA knot scales with the 3D Flory exponent within error. In (ii), we find , a value between the 3D
and 2D () exponents, indicating an incomplete 2D relaxation or a
different polymer universality class. Compelling evidence is also presented for
the localization of the knot crossings in 2D.Comment: 4 pages, 3 figure
Effects of Social Identity, Self-Esteem, Schooling, and Age on Hope [Efectos de la Identidad Social, la autoestima, la Escolaridad y la Edad sobre la esperanza]
AbstractThe primary objective of this study was to analyze the direct explanatory power of social identity, schooling, and age on self-esteem, as well as the indirect effects of those variables (through the mediating variable self-esteem) on hope. A non-probabilistic sample composed of 657 persons from southern Nuevo Leon was recruited (mean age = 39.75 years; SD = 16.96). Structural equation modeling was used to analyze the effects, both direct and indirect, of the independent variables upon the dependent variables. With regard to hope, the model yields an explained variance of 37% (d ≥ 26% = large effect size) and shows well goodness-of-fit indices: χ2 / df = 2.618, GFI = .997, AFGI = .978, CFI = .995, NNFI = .995, NFI = .992, RMSEA = .048 (IC90%, .001, .100), and SRMR = .017. It is concluded that social identity, together with some contextual variables of a personal nature (for instance, age and schooling) is probably very important to explain the levels of self-esteem and hopeResumenEl objetivo primario de este estudio fue analizar el poder explicativo de las variables identidad social, escolaridad y edad, directamente sobre la autoestima y los efectos indirectos de las tres primeras, a través de la autoestima, sobre la esperanza. Se realizó el estudio en una muestra no probabilística de 657 hombres y mujeres, con edad promedio de 39.75 años (DE = 16.96). Se usó modelamiento de ecuaciones estructurales para analizar los efectos, tanto directos como indirectos, de las variables independientes sobre las dependientes. Se encuentra que el modelo tiene una varianza explicada del 37% (d = ≥ 26% = tamaño del efecto grande) en esperanza, con buenos indicadores de bondad de ajuste: χ2/gl = 2.618; GFI = .997; AFGI = .978; CFI = .995; NNFI = .995; NFI = .992; RMSEA = .048 (IC90%, .000, .100), SRMR = .017. Se concluye que probablemente la identidad social, junto con algunas variables contextuales de tipo personal, como la edad y la escolaridad, es prioritaria para explicar la existencia de la autoestima y de la esperanza
Efeito de fatores de processo na atividade holocelulolítica e no crescimento micelial de Lentinula edodes.
Resumo. Disponível online. MIPE
Efeito de gramíneas forrageiras sobre a germinação carpogênica de Sclerotinia sclerotiorum e atividade microbiana do solo.
O mofo branco, causado por Sclerotinia sclerotiorum (Ss), é uma doença severa que infecta várias culturas e é de difícil controle. Uma das estratégias de manejo da doença é por meio do uso de gramíneas forrageiras, visando-se a redução do inóculo do patógeno no solo. Objetivando-se avaliar o efeito de gramíneas forrageiras sobre a germinação carpogênica de Ss e atividade microbiana (AM) do solo, realizou-se este trabalho
Anomalies in Superfluids and a Chiral Electric Effect
We analyze the chiral transport terms in relativistic superfluid
hydrodynamics. In addition to the spontaneously broken symmetry current, we
consider an arbitrary number of unbroken symmetries and extend the results of
arXiv:1105.3733. We suggest an interpretation of some of the new transport
coefficients in terms of chiral and gravitational anomalies. In particular, we
show that with unbroken gauged charges in the system, one can observe a chiral
electric conductivity - a current in a perpendicular direction to the applied
electric field. We present a motivated proposal for the value of the associated
transport coefficient, linking it to the triangle anomaly. Along the way we
present new arguments regarding the interpretation of the anomalous transport
coefficients in normal fluids. We propose a natural generalization of the
chiral transport terms to the case of an arbitrary number of spontaneously
broken symmetry currents.Comment: 30 pages; v2: Onsager-relations argument corrected, references added;
v3: fixed missing line in eq. (38
Pressure-induced charge ordering transition in CaMn7O12
We use high-pressure resistivity and single crystal x-ray diffraction at ambient and low temperature to investigate the charge ordering phase transition of CaMn 7 O 12 . We have found that at ambient temperature the Jahn-Teller distortion of the Mn 3 + O 6 octahedra rapidly decreases above 20 GPa, and vanishes at 28 GPa, when two Mn octahedral sites initially occupied by Mn 3 + and Mn 4 + become regular and equivalent as the result of a charge delocalization. Such a change correlates with a two orders of magnitude drop in the resistivity and a symmetry increase from the low-pressure rhombohedral R ¯ 3 phase to the cubic Im ¯ 3 structure, the same as one found at ambient pressure above 440 K. This yields the slope of the charge ordering phase boundary of d T c / d p ? ? 6 K/GPa. This result is further supported by the lack of a structural phase transition up to the maximum measured pressure of 30 GPa when the experiment is performed at 70 K. The satellite reflections of the structural modulation of the multiferroic phase of CaMn 7 O 12 observed at 70 K were found to hold up to 25 GPa with the structure keeping a constant modulation vector k = ( 0 0 0.925 ) with pressure. The average structure at 70 K does not show other indications of further phase transition.Y. Li and X. Du from Peking University are greatly acknowledged for growing and providing the CaMn7O12 crystals. D. Spahr and J. König from Goethe University are acknowledged for help with the single-crystal diffraction experiments. M.S. would like to acknowledge the financial support under the DFG-ANR Grant No. WI1232/41-1 and DFG GACR Project No. WI3320/3-1. V.M. and J.R.-F. thank the financial support from the Spanish Ministerio de Ciencia e Innovación (MICINN) for the Beatriz Galindo Program (BG20/000777) and for the Project No. PGC2018-097520- A-I00, respectively. DESY Photon Science is gratefully acknowledged. PETRA III at DESY is a member of the Helmholtz Association (HGF)
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