2025/12/11 by Marcos V. de S. Silva, Carlos F. S. Pereira, Silva, Marcos V. de S. +11
Physics and Astronomy · #Cosmology and Gravitation Theories #Pulsars and Gravitational Waves Research #Statistical Mechanics and Entropy
paper · pdf · doi:10.1088/1361-6382/ae85a8
Abstract In this work, we analyze some matter sources associated with wormhole models within a k-essence theory coupled to the gravitational sector through a phantom scalar field. We adopt a spherically symmetric background in (3+1) dimensions and consider two types of systems: electrically and magnetically charged. In the first case, we consider the generalized Ellis–Bronnikov model, in which we fix the power of the kinetic term in the k-essence Lagrangian function to <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:mrow> <mml:mi>n</mml:mi> <mml:mo>=</mml:mo> <mml:mn>1</mml:mn> <mml:mrow> <mml:mo>/</mml:mo> </mml:mrow> <mml:mn>2</mml:mn> </mml:mrow> </mml:math> and take the parameter <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:mrow> <mml:mi>m</mml:mi> <mml:mtext>⩾</mml:mtext> <mml:mn>2</mml:mn> </mml:mrow> </mml:math> , which acts as a generalization factor for the geometry of the wormhole area function. From this, we obtained the expression for the scalar field, the potential, and the associated electromagnetic functions for any values of the parameter <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:mrow> <mml:mi>m</mml:mi> <mml:mtext>⩾</mml:mtext> <mml:mrow> <mml:mn>2</mml:mn> </mml:mrow> </mml:mrow> </mml:math> . In the second and third models, we consider the scenario of two wormholes that are structured according to the adjustment of the parameters that define the metric component associated with the area function <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:mrow> <mml:msup> <mml:mi mathvariant="normal">Σ</mml:mi> <mml:mn>2</mml:mn> </mml:msup> </mml:mrow> </mml:math> (the <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:mrow> <mml:msub> <mml:mi>g</mml:mi> <mml:mrow> <mml:mn>22</mml:mn> </mml:mrow> </mml:msub> </mml:mrow> </mml:math> component of the line element), and in both cases we adopt <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:mrow> <mml:mi>n</mml:mi> <mml:mo>=</mml:mo> <mml:mn>1</mml:mn> <mml:mrow> <mml:mo>/</mml:mo> </mml:mrow> <mml:mn>2</mml:mn> </mml:mrow> </mml:math> . We show that the violation of the null energy conditions is conditioned by the parameters of the area function. Finally, we studied the linear stability of the models through the behavior of a test scalar field using both the WKB method and the time-domain evolution method.