Modified gravity versus shear viscosity: Imprints on the scalar matter perturbations

C. M. S. Barbosa; H. Velten; J. C. Fabris; Rudnei O. Ramos

doi:10.1103/physrevd.98.123522

Modified gravity versus shear viscosity: Imprints on the scalar matter perturbations

Physical Review D ◽

10.1103/physrevd.98.123522 ◽

2018 ◽

Vol 98 (12) ◽

Cited By ~ 2

Author(s):

C. M. S. Barbosa ◽

H. Velten ◽

J. C. Fabris ◽

Rudnei O. Ramos

Keyword(s):

Shear Viscosity ◽

Modified Gravity ◽

Scalar Matter

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Backreaction effects due to matter coupled higher derivative gravity

Modern Physics Letters A ◽

10.1142/s0217732315500650 ◽

2015 ◽

Vol 30 (16) ◽

pp. 1550065 ◽

Cited By ~ 2

Author(s):

Lata Kh Joshi ◽

P. Ramadevi

Keyword(s):

Shear Viscosity ◽

Quark Gluon Plasma ◽

Transport Coefficients ◽

Gluon Plasma ◽

Entropy Density ◽

Flow Measurements ◽

Strongly Coupled ◽

Higher Derivative ◽

Scalar Matter ◽

Dimensional Spacetime

AdS-hydrodynamics has proven to be a useful tool for obtaining transport coefficients observed in the collective flow of strongly coupled fluids like quark gluon plasma (QGP). Particularly, the ratio of shear viscosity to entropy density η/s obtained from elliptic flow measurements can be matched with the computation done in the dual gravity theory. The experimentally observed temperature dependence of η/s requires the study of scalar matter coupled AdS gravity including higher derivative curvature corrections. We obtain the backreaction to the metric for such a matter coupled AdS gravity in D-dimensional spacetime due to the higher derivative curvature corrections. Then, we present the backreaction corrections to shear viscosity η and entropy density s.

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Effects of hoop stress, initial shear stress, and shear viscosity ratio on the steady two-phase fiber spinning

International Journal of Multiphase Flow ◽

10.1016/s0301-9322(97)88384-x ◽

1996 ◽

Vol 22 ◽

pp. 124

Author(s):

W Lee

Keyword(s):

Shear Stress ◽

Shear Viscosity ◽

Hoop Stress ◽

Viscosity Ratio ◽

Fiber Spinning ◽

Two Phase

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An Assessment of Red Cell Deformability Using a Simple Filtration Method

10.1055/s-0038-1665788 ◽

1979 ◽

Author(s):

M Drummond ◽

G Lowe ◽

J Belch ◽

C Forbes ◽

J Barbenel

Keyword(s):

Cell Count ◽

Shear Viscosity ◽

White Cell Count ◽

White Cell ◽

Red Cell ◽

Cell Deformability ◽

Red Cell Deformability ◽

Simple Method ◽

Filtration Method ◽

Significant Difference

We investigated the reproducibility and validity of a simple method of measuring red cell deformability (filtration of whole blood through 5 µ sieves) and its relationship to haematocrit, blood viscosity, fibrinogen, white cell count, sex and smoking. The mean coefficient of variation in normals was 3. 7%. Tanned red cells showed marked loss of deformability. Blood filtration rate correlated with haematocrit (r = 0. 99 on dilution of samples, r = 0. 7 in 120 normals and patients). After correction for haematocrit, deformability correlated with high shear viscosity, but not low shear viscosity, fibrinogen or white cell count. In 60 normals there was no significant difference between males and females, or smokers and non-smokers, but in 11 smokers there was an acute fall in deformability after smoking 3 cigarettes (p<0. 05). Reduced deformability was found in acute myocardial infarction (n = 15, p<0. 01) and chronic peripheral arterial disease (n = 15, p<0. 01). The technique is reproducible, detects rigid cells and appears useful in the study of vascular disease.

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