NON-SINGULAR GLOBAL COSMIC STRINGS

2005 ◽  
Vol 20 (11) ◽  
pp. 2374-2379
Author(s):  
Y. VERBIN ◽  
A. L. LARSEN
Keyword(s):  
Scalar Field ◽  
Cosmic Strings ◽  
Weak Field ◽  
Stationary Solutions ◽  
Linear Sigma Model ◽  
Complex Scalar ◽  
Potential Term ◽  
Weak Field Limit ◽  
Complex Scalar Field ◽  
Kaluza Klein

Non-singular global cosmic strings are found in a non-linear sigma model with a potential term for a self-gravitating complex scalar field. Stationary solutions with angular momentum and possibly linear momentum are obtained by assuming an oscillatory dependence of the scalar field on t, φ and z. This dependence has an effect similar to gauging the global U(1) symmetry of the model, which is actually a Kaluza-Klein reduction from four to three spacetime dimensions. The method of analysis can be regarded as an extension of the gravito-electromagnetism formalism beyond the weak field limit.

THE ORDER PARAMETER FIELD FOR COSMIC STRING, INFLATION AND DARK ENERGY

2003 ◽  
Vol 18 (36) ◽  
pp. 2587-2597 ◽  
Author(s):  
PENG-MING ZHANG ◽  
YI-SHI DUAN ◽  
LI-MING CAO
Keyword(s):  
Dark Energy ◽  
Scalar Field ◽  
Early Universe ◽  
Cosmic String ◽  
Order Parameter ◽  
Cosmic Strings ◽  
Complex Scalar ◽  
Parameter Field ◽  
Complex Scalar Field

We present a whole frame for the cosmic strings, inflation and dark energy with the complex scalar field which can be regarded as the order parameter of our universe. One can find that the comic strings emerge in the zeros of the complex scalar field in the early universe. And with the evolution of complex scalar field, inflation and dark energy can be understood in this frame.

GALACTIC AND ASTROPHYSICAL SIZES FROM SCALAR-TENSOR THEORY OF GRAVITY

2004 ◽  
Vol 13 (02) ◽  
pp. 359-371 ◽  
Author(s):  
GIUSEPPE BASINI ◽  
MARCO RICCI ◽  
FULVIO BONGIORNO ◽  
SALVATORE CAPOZZIELLO
Keyword(s):  
Scalar Field ◽  
Spiral Galaxies ◽  
Weak Field ◽  
Newtonian Potential ◽  
Scalar Tensor Theory ◽  
Field Limit ◽  
Weak Field Limit ◽  
Tensor Theory ◽  
Flat Rotation Curves ◽  
Theory Of Gravity

We investigate the weak-field limit of scalar-tensor theory of gravity and show that results are directly depending on the coupling and self-interaction potential of the scalar field. In particular, corrections are derived for the Newtonian potential. We discuss astrophysical applications of the results, in particular the flat rotation curves of spiral galaxies.

The classical and quantum cosmology with a complex scalar field

1992 ◽  
Vol 169 (4) ◽  
pp. 308-312 ◽  
Author(s):  
I.M. Khalatnikov ◽  
A. Mezhlumian
Keyword(s):  
Scalar Field ◽  
Quantum Cosmology ◽  
Complex Scalar ◽  
Complex Scalar Field

Self-interacting complex scalar field as dark matter

2011 ◽  
Author(s):  
F. Briscese ◽  
Luis Arturo Ureña-López ◽  
Hugo Aurelio Morales-Técotl ◽  
Román Linares-Romero ◽  
Elí Santos-Rodríguez ◽  
...  
Keyword(s):  
Dark Matter ◽  
Scalar Field ◽  
Complex Scalar ◽  
Complex Scalar Field

scholarly journals Hadamard parametrix of the Feynman Green’s function of a five-dimensional charged scalar field

2020 ◽  
Vol 29 (11) ◽  
pp. 2041002
Author(s):  
Visakan Balakumar ◽  
Elizabeth Winstanley
Keyword(s):  
Scalar Field ◽  
Green’S Function ◽  
Green's Function ◽  
Minkowski Spacetime ◽  
Energy Tensor ◽  
Complex Scalar ◽  
Charged Scalar ◽  
Taylor Series Expansions ◽  
Complex Scalar Field ◽  
Charged Scalar Field

The Hadamard parametrix is a representation of the short-distance singularity structure of the Feynman Green’s function for a quantum field on a curved spacetime background. Subtracting these divergent terms regularizes the Feynman Green’s function and enables the computation of renormalized expectation values of observables. We study the Hadamard parametrix for a charged, massive, complex scalar field in five spacetime dimensions. Even in Minkowski spacetime, it is not possible to write the Feynman Green’s function for a charged scalar field exactly in closed form. We, therefore, present covariant Taylor series expansions for the biscalars arising in the Hadamard parametrix. On a general spacetime background, we explicitly state the expansion coefficients up to the order required for the computation of the renormalized scalar field current. These coefficients become increasingly lengthy as the order of the expansion increases, so we give the higher-order terms required for the calculation of the renormalized stress-energy tensor in Minkowski spacetime only.

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