305 research outputs found

### QCD Chiral restoration at finite $T$ under the Magnetic field: Studies based on the instanton vacuum model

We investigate the chiral restoration at finite temperature $(T)$ under the
strong external magnetic field $\vec{B}=B_{0}\hat{z}$ of the SU(2) light-flavor
QCD matter. We employ the instanton-liquid QCD vacuum configuration accompanied
with the linear Schwinger method for inducing the magnetic field. The
Harrington-Shepard caloron solution is used to modify the instanton parameters,
i.e. the average instanton size $(\bar{\rho})$ and inter-instanton distance
$(\bar{R})$, as functions of $T$. In addition, we include the meson-loop
corrections (MLC) as the large-$N_{c}$ corrections because they are critical
for reproducing the universal chiral restoration pattern. We present the
numerical results for the constituent-quark mass as well as chiral condensate
which signal the spontaneous breakdown of chiral-symmetry (SB$\chi$S), as
functions of $T$ and $B$. Besides we find that the changes for the $F_\pi$ and
$m_\pi$ due to the magnetic field is relatively small, in comparison to those
caused by the finite $T$ effect.Comment: 4 pages, 1 table, 6figs. arXiv admin note: significant text overlap
with arXiv:1103.605

### Hyperbolic calorons, monopoles, and instantons

We construct families of SO(3)-symmetric charge 1 instantons and calorons on
the space H^3 x R. We show how the calorons include instantons and hyperbolic
monopoles as limiting cases. We show how Euclidean calorons are the flat space
limit of this family.Comment: 11 pages, no figures 1 reference added Published version available
at: http://www.springerlink.com/content/k0j4815u54303450

### SU(2) Calorons and Magnetic Monopoles

We investigate the self-dual Yang-Mills gauge configurations on $R^3\times
S^1$ when the gauge symmetry SU(2) is broken to U(1) by the Wilson loop. We
construct the explicit field configuration for a single instanton by the Nahm
method and show that an instanton is composed of two self-dual monopoles of
opposite magnetic charge. We normalize the moduli space metric of an instanton
and study various limits of the field configuration and its moduli space
metric.Comment: 17 pages, RevTex, 1 Figur

### ADHM/Nahm Construction of Localized Solitons in Noncommutative Gauge Theories

We study the relationship between ADHM/Nahm construction and ``solution
generating technique'' of BPS solitons in noncommutative gauge theories.
ADHM/Nahm construction and ``solution generating technique'' are the most
strong ways to construct exact BPS solitons. Localized solitons are the
solitons which are generated by the ``solution generating technique.'' The
shift operators which play crucial roles in ``solution generating technique''
naturally appear in ADHM/Nahm construction and we can construct various exact
localized solitons including new solitons: localized periodic instantons
(=localized calorons) and localized doubly-periodic instantons. Nahm
construction also gives rise to BPS fluxons straightforwardly from the
appropriate input Nahm data which is expected from the D-brane picture of BPS
fluxons. We also show that the Fourier-transformed soliton of the localized
caloron in the zero-period limit exactly coincides with the BPS fluxon.Comment: 30 pages, LaTeX, 3 figures; v3: minor changes, references added; v4:
references added, version to appear in PR

### Genetic and growth differences in the outcrossings between two clonal strains of the self-fertilizing mangrove killifish

The populations of the only known self-fertilizing vertebrate Kryptolebias marmoratus (Poey, 1880) (formerly known as Rivulus marmoratus Poey, 1880; Cyprinodontiformes: Aplocheilidae) usually consist of different homozygous lineages; however, heterozygous individuals are found occasionally and ratios of homozygosity and heterozygosity in populations are dependent on the proportion of males. However, it is still unclear what impact male-mediated genetic diversity has on the phenotype of K. marmoratus. To clarify this, we attempted outcrossing between male and hermaphrodite of two different clonal strains with different life-history traits using artificial insemination, and examined the genotypes and growth of the hybrid F2 generation. We detected genetic differences between the two clonal strains using amplified fragment length polymorphism (AFLP) analysis with 3 primer combinations, and then obtained 11 AFLP markers. From a total of 31 artificial inseminations with two clonal strains, 1 of 13 hatched fish clearly indicated heterozygosity. The hybrid F2 generations were also heterozygous. Moreover, the growths of the hybrid F2 generation were intermediate of the parental strains from days 0 to 30. Therefore, outcrossing changes genetic architecture and the new genotypes potentially result in new phenotypes of the subsequent generations of K. marmoratus. It may also play a role in adaptation to new environments and the facilitation of local adaptation

### QED in a Strong External Magnetic Field: Beyond the Constant Mass Approximation

We solve the Schwinger-Dyson equations for QED in 2+1 or 3+1 dimensions in
the presence of a strong homogeneous external magnetic field. The magnetic
field is assumed strong enough, so that the lowest Landau level approximation
holds, but the usual assumption of a momentum-independent self-energy is not
made. In 2+1 dimensions, the scaling with logarithm changes to a square root
dependence on the magnetic field, but the most spectacular result takes place
in 3+1 dimensions, where the constant mass approximation turns out to be
unreliable and the (momentum-dependent) dynamical mass is larger by several
orders of magnitude compared to what has been found till now using the constant
mass approximation.Comment: 21 pages, 8 figures, plain latex, references adde

### Emergence of Skyrme crystal in Gross-Neveu and 't Hooft models at finite density

We study two-dimensional, large $N$ field theoretic models (Gross-Neveu
model, 't Hooft model) at finite baryon density near the chiral limit. The same
mechanism which leads to massless baryons in these models induces a breakdown
of translational invariance at any finite density. In the chiral limit baryonic
matter is characterized by a spatially varying chiral angle with a wave number
depending only on the density. For small bare quark masses a sine-Gordon kink
chain is obtained which may be regarded as simplest realization of the Skyrme
crystal for nuclear matter. Characteristic differences between confining and
non-confining models are pointed out.Comment: 27 pages, 11 figures, added reference, corrected sig

### Probable antenatal depression at antiretroviral initiation and postpartum viral suppression and engagement in care

Objective: To estimate the association of probable antenatal depression with postpartum HIV care engagement among pregnant women in Malawi. Design: We conducted a prospective cohort study of 299 women who were initiating antiretroviral therapy (ART) through Option B+ at a government antenatal clinic in Malawi. Methods: Probable antenatal depression was assessed on the day of ART initiation with the validated Chichewa version of the Edinburgh Postnatal Depression Scale (EPDS). We estimated crude and adjusted risk differences (RD, aRD) of visit attendance and prevalence differences (PD, aPD) of viral suppression through 12 months post-ART initiation comparing women with versus without probable antenatal depression. Results: One in 10 women had probable antenatal depression. Most women were engaged in care through 12 months post-ART initiation: 85% attended all scheduled ART visits, and 81% were in care and virally suppressed. Women with and without probable antenatal depression had a comparable probability of attending all scheduled visits (RD: -0.02; 95% CI -0.16 to 0.12; aRD: -0.04; 95% CI -0.18 to 0.10), and of viral suppression (PD: -0.02; 95% CI -0.17 to 0.13; aPD: -0.01; 95% CI -0.17 to 0.15) in crude and adjusted analyses. Conclusion: Probable antenatal depression was not associated with engagement in HIV care through 12 months post-ART initiation. In a population with high HIV care engagement, antenatal depression may not impair HIV-related outcomes

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