Brans-Dicke-Maxwell Solutions for Higher Dimensional Static Cylindrical Symmetric Spacetime

In this paper, Brans-Dicke-Maxwell type vacuum solutions are considered for a static cylindrically symmetric spacetime in arbitrary dimensions. Exact solutions are obtained by directly solving the field equations for the case where an azimuthal magnetic field is present. Other configurations such as axial magnetic field case can be obtained by suitably relabeling the coordinates. We have also considered conformally related "Einstein frame" to relate the solutions we have obtained with the dilaton-Maxwell type solutions that exist in the literature. We see that for a special case the general solution we present reduces to Dilaton-Melvin spacetime. The General Relativistic limit of these solutions are also discussed and we found that this limit is different from the four dimensional case.Comment: 9 Pages, articl

Cylindrically Symmetric Vacuum Solutions in Higher Dimensional Brans-Dicke Theory

Higher dimensional, static, cylindrically symmetric vacuum solutions with and without a cosmological constant in the Brans-Dicke theory are presented. We show that, for a negative cosmological constant and for specific values of the parameters, a particular subclass of these solutions include higher dimensional topological black hole-type solutions with a flat horizon topology. We briefly extend our discussion to stationary vacuum and $\Lambda-$vacuum solutions.Comment: V3: Published Versio

Schwarzschild-De Sitter black holes in 4+1 dimensional bulk

We construct a static solution for 4+1 dimensional bulk such that the 3+1 dimensional world has a linear warp factor and describes the Schwarzschild-dS_{4} black hole. For m=0 this four dimensional universe and Friedmann Robertson Walker universe are related with an explicit coordinate transformation. We emphasize that for linear warp factors the effect of bulk on the brane world shows up as the dS_{4} background which is favored by the big bang cosmology.Comment: 6 page

Higher Dimensional Cylindrical or Kasner Type Electrovacuum Solutions

We consider a D dimensional Kasner type diagonal spacetime where metric functions depend only on a single coordinate and electromagnetic field shares the symmetries of spacetime. These solutions can describe static cylindrical or cosmological Einstein-Maxwell vacuum spacetimes. We mainly focus on electrovacuum solutions and four different types of solutions are obtained in which one of them has no four dimensional counterpart. We also consider the properties of the general solution corresponding to the exterior field of a charged line mass and discuss its several properties. Although it resembles the same form with four dimensional one, there is a difference on the range of the solutions for fixed signs of the parameters. General magnetic field vacuum solution are also briefly discussed, which reduces to Bonnor-Melvin magnetic universe for a special choice of the parameters. The Kasner forms of the general solution are also presented for the cylindrical or cosmological cases.Comment: 16 pages, Revtex. Text and references are extended, Published versio

Do stock markets follow a random walk? New evidence for an old question

This paper re-examines whether the stock markets are efficient or not by focusing the role of cross-sectional dependency and structural breaks with newly developed panel unit root tests proposed by Lee, Wu, and Yang (2016) and Nazlioglu and Karul (2017). To do this, we used 33 countries stock price indexes for the period 1992M05 – 2018M05. Our results indicate that (i) accounting for cross-sectional dependency and structural breaks play an important role for better understanding the behavior of the stock market indices, (ii) recent testing methodologies provide a strong evidence for the weak-form efficiency of stock markets, (iii) the stationarity property of series is consistent regardless of whether capturing structural shifts as sharp or gradual process, (iv) modelling approach to cross-section dependency matters for deciding whether stock prices can be characterized as random walk or mean reversion processes. © 2019 Elsevier Inc

Endocan, TGF-beta, and ADMA as Risk Factors for Endothelial Dysfunction and Possible Vascular Disease in Patients with Subclinical Hypothyroidism

Purpose: Although the relationship between atherosclerosis and overt hypothyroidism has been confirmed, it remains controversial in cases of subclinical hypothyroidism. Higher TSH and similar T4 suggest differences in set-points or differences due to diagnostic limitations regarding subclinical hypothyroidism. Endothelial dysfunction (ED) is a marker rather than a precursor of cardiovascular disease. Asymmetric dimethylarginine (ADMA) and endocan are known as novel markers of ED in various diseases. Transforming growth factor-beta (TGF-beta) has a protective role against autoimmune diseases such as thyroiditis. This study aimed to determine the relationships between serum ADMA, endocan, TGF-beta, and the high-sensitivity C-reactive protein (hs-CRP) levels, a proven indicator of ED, in patients with SH. Methods. Thirty-five patients with SH and 21 age- and sex-matched euthyroid subjects were included in the study. The levels of TSH, FT4, lipid parameters, endocan, ADMA, TGF-beta, and hs-CRP were measured. Results: No significant differences in age or sex were found between the patient and control groups (p=0.294 and 0.881, respectively). Mean TSH level was higher in the patient group (p=0.005), whereas mean fT4 level was similar in two groups (p=0.455). The average hs-CRP, endocan, TGF-beta l level in the patient group was higher than control group (p=0.001; P=0.012; P=0.025; P<0.01 respectively). A positive correlation was found between the endocan and ADMA levels (r=0.760, p=0.000). ADMA levels also were positively correlated with hs-CRP. Both the TSH and low-density lipoprotein cholesterol (LDL-C) levels were positively correlated with the hs-CRP level. Conclusions: Subclinical hypothyroidism is associated with increased levels of serum endocan, ADMA, and TGF-beta, which are new markers for ED. In particular, ADMA was correlated with both endocan and hs-CRP levels. These findings are suggestive for increased risk of ED and subsequent development of atherosclerosis in patients with SH