Magnetized Kantowski-Sachs bulk viscous string cosmological models with decaying vaccum energy density Lambda(t)

被引:0
作者
Das, Kanika [1 ]
Ali, Nawsad [1 ]
机构
[1] Gauhati Univ, Dept Math, Gauhati, Assam, India
来源
TURKISH JOURNAL OF PHYSICS | 2014年 / 38卷 / 02期
关键词
Kantowski-Sachs universe; bulk viscous; magnetized cosmic string; variable cosmological constant;
D O I
10.3906/fiz-1311-11
中图分类号
O4 [物理学];
学科分类号
0702 ;
摘要
In this paper, we deal with bulk viscous magnetized Kantowski{Sachs string cosmological models in the presence of time variable cosmological term Lambda. To obtain a deterministic model, we assume the conditions sigma infinity theta and zeta theta - constant, where sigma is the shear, theta the expansion in the model, and zeta the coefficient of bulk viscosity. The value of cosmological constant for the models is found to be small and positive, which is supported by the results from recent observations (SN 1a). The behavior of the model in the presence and absence of magnetic fields together with physical and geometrical aspects is also discussed.
引用
收藏
页码:193 / 202
页数:10
相关论文
共 65 条
[1]   NONSINGULAR COSMOLOGY WITH A TIME-DEPENDENT COSMOLOGICAL TERM [J].
ARBAB, AI ;
ABDELRAHMAN, AMM .
PHYSICAL REVIEW D, 1994, 50 (12) :7725-7728
[2]   Dynamical solution to the problem of a small cosmological constant and late-time cosmic acceleration [J].
Armendariz-Picon, C ;
Mukhanov, V ;
Steinhardt, PJ .
PHYSICAL REVIEW LETTERS, 2000, 85 (21) :4438-4441
[3]   EXTRAGALACTIC MAGNETIC-FIELDS [J].
ASSEO, E ;
SOL, H .
PHYSICS REPORTS-REVIEW SECTION OF PHYSICS LETTERS, 1987, 148 (06) :307-436
[4]   Bianchi type-III string cosmological models with time dependent bulk viscosity [J].
Bali, Raj ;
Pradhan, Anirudh .
CHINESE PHYSICS LETTERS, 2007, 24 (02) :585-588
[5]   STRING COSMOLOGY IN BIANCHI-I SPACE-TIME [J].
BANERJEE, A ;
SANYAL, AK ;
CHAKRABORTY, S .
PRAMANA-JOURNAL OF PHYSICS, 1990, 34 (01) :1-11
[6]   COSMOLOGICAL MODELS WITH A VARIABLE COSMOLOGICAL TERM AND BULK VISCOUS MODELS [J].
BEESHAM, A .
PHYSICAL REVIEW D, 1993, 48 (08) :3539-3543
[7]   First-year Wilkinson Microwave Anisotropy Probe (WMAP) observations:: Preliminary maps and basic results [J].
Bennett, CL ;
Halpern, M ;
Hinshaw, G ;
Jarosik, N ;
Kogut, A ;
Limon, M ;
Meyer, SS ;
Page, L ;
Spergel, DN ;
Tucker, GS ;
Wollack, E ;
Wright, EL ;
Barnes, C ;
Greason, MR ;
Hill, RS ;
Komatsu, E ;
Nolta, MR ;
Odegard, N ;
Peiris, HV ;
Verde, L ;
Weiland, JL .
ASTROPHYSICAL JOURNAL SUPPLEMENT SERIES, 2003, 148 (01) :1-27
[8]   A phantom menace? Cosmological consequences of a dark energy component with super-negative equation of state [J].
Caldwell, RR .
PHYSICS LETTERS B, 2002, 545 (1-2) :23-29
[9]   COSMOLOGICAL CONSEQUENCES OF A TIME-DEPENDENT LAMBDA TERM [J].
CARVALHO, JC ;
LIMA, JAS ;
WAGA, I .
PHYSICAL REVIEW D, 1992, 46 (06) :2404-2407
[10]  
CHAKRABORTY S, 1991, INDIAN J PURE AP PHY, V29, P31