{"content":[{"text":"260","bbox":{"left":0.168111,"top":0.123007,"width":0.02529200000000001,"height":0.015785999999999994}},{"text":"Atul Tyagi, Jaipal Singh and Gajendra Pal Singh","bbox":{"left":0.505727,"top":0.123007,"width":0.32711599999999996,"height":0.015785999999999994}},{"text":"of state (p = ) to the matter content of the universe in the early state of evolution of \n universe. Wesson [20] has investigated an exact solution of Einstein's field equation with \n Stiff fluid equation of state. Mohanty et al. [10] have investigated cylindrically symmetric \n Zel'dovich fluid distribution in general relativity. \n Bali and Sharma [4] have investigated Bianchi type-I stiff fluid magnetized cosmological \n model in General Relativity. \n In the early universe, all the investigations dealing with physical process use a model of \n the universe usually called a big-bang model. The big-band model based on Einstein field \n equation successfully explains the three important observation in Astronomy : (i) The \n phenomena of expanding universe, (ii) Primordial nucleo synthesis, (iii) The observed \n isotropy of the cosmic background radiation. \n The astronomical observation in the late eighties has revealed that the predications of \n FRW type models do not always meet with our requirements as we believe earlier, the big \n bang model is known to have the following short comings : \n (i) The model has singularity in the past and possibly one in future. \n (ii) The conservation of energy is violated in the big-bang model. \n (iii) The big-bang models based on reasonable equations of state lead to a very small \n particle horizon in the early epochs of the universe. This fact gives rise to the \n 'Horizon problem'. \n (iv) No consistent scenario exists within the frame work of big-bang model that explains \n the origin, evaluation and characteristic of structure in the universe of small scales. \n (v) Flatness problem \n Thus alternative theories were proposed from time to time. The most well known theory \n is the 'Steady State Theory' by Bondi and Gold. In this theory the universe does not have \n any singular beginning nor an end on the cosmic time scale to maintain constancy of \n matter density. They envisaged a very slow but continuous creation of matter in contrast \n to the irrespective certain at t = 0 of the standard FRW model. However, it suffers the \n serious disqualification for not giving any physical justification in the form of any \n dynamical theory for continuous creation of matter, also the principle energy \n conservation is scarifies in this formulism. \n To remove this problem, Hoyle and Narlikar [8] adopted a field theoretic approach \n introducing a massless and chargeless scalar field in Einstein Hilbert action to account for \n creation of matter. In C-field theory, there is no big-bang type singularity as in the steady \n state theory of Bondi and Gold [6], Narlikar and Padmanabhan [11] have investigated the \n solution of Einstein's field equation which admit radiation and negative energy massless \n scalar c-field as source. Bali and Tikekar [3] have investigated C-field cosmological \n model for dust distribution in Flat FRW model with variable gravitation constant.","bbox":{"left":0.168111,"top":0.167564,"width":0.666488,"height":0.629939}}],"images_bbox":[],"images_bbox_not_text_overlap":[]}