Wormhole Geometry Research Articles

Impact of dark matter galactic halo models on wormhole geometry within f(Q,T) gravity

This study investigates the possible existence of wormhole solutions with dark matter galactic halo profiles in the background of f(Q,T) gravity. The primary focus of the current study is to find the significance of dark matter (DM) in the search for traversable wormhole solutions within galactic halos. Various dark matter profiles, such as Universal Rotation Curves (URC), Navarro-Frenk-White (NFW) model-I, and NFW model-II, are examined within two different f(Q,T) models. The DM halo density profiles generate appropriate shape functions under the linear model that satisfy all the essential conditions for presenting the wormhole geometries. Apart from that, we take into account an embedded wormhole-specific shape function to inspect DM profiles under the non-linear model. We noticed that the null energy conditions are violated by the obtained solution from each model, which confirms that the DM support wormholes to sustain in the galactic halo. The findings reveal that the solutions obtained for different density profiles of dark matter halos within generalized symmetric teleparallel gravity demonstrate viability.

Generalized wormhole models within galactic halo region in torsion and matter coupling gravity formalism

In the current analysis, we investigate the possible existence of generalized Wormhole models within the galactic halo region by analyzing specific dark matter models. The observational data is checked in the framework of torsion within minimal matter coupling gravity. By using the variational approach modified versions of the field equations under the anisotropic source of matter are calculated. To discuss the specific necessary characteristics of the embedded wormhole geometry, we have analyzed the energy conditions under the effect of dark matter halos. We consider two embedded wormhole-specific shape functions in terms of the tortoise coordinate for the current study. Further, we compare different wormhole solutions for the different regional ranges depending on the involved parametric values. To check the effect of the dark matter halos, we use the observational data within the signature of the M87 galaxy and the Milky Way galaxy.

Exploring the applicability of traversable wormhole formation in [formula omitted] gravity

In this work, we construct three different models of static wormhole (WH) geometries within the realm of f(R,Lm) gravity theory. We start by deriving the corresponding field equations for the Morris–Thorne WH geometry in the context of anisotropic matter distribution under the generic form of f(R,Lm) gravity. By adequately specifying the key features of three different shape function models generated with different assumptions about their matter content, and assuming that WHs exert no tidal force by setting the gravitational redshift function to be a constant or φ′(r)=0, we disclose a variety of exact WH solutions in the theory. Our exact solutions for f(R,Lm) show that for all three classes of WHs found, the energy density is consistently positive in all spacetime, while the radial pressure is negative. This signifies that exotic matter is mandatory for the existence of WHs in f(R,Lm) gravity. We have also applied the energy conditions (ECs) for the WHs’ physical content and found that exact WH models are filled with exotic matter that violates the necessary ECs throughout spacetime and makes them compatible and traversable.

Traversable wormholes with weak gravitational lensing effect in [formula omitted] gravity

In this article, we have introduced completely new asymptotically flat Morris-Thorne traversable wormhole geometries supported by anisotropic matter in the framework of f(R,T)=R+αR2+λT gravity whereas the isotropic matter content does not support the wormhole structure. The reported shape functions are nicely fitted in the construction of wormhole geometries by satisfying all the essential conditions. The wormhole solutions are regular at the throat radius and in the equilibrium position under the action of hydrostatic and anisotropic forces only. In addition, we have studied the weak gravitational lensing effect in the reported wormhole optical geometries using the Gauss–Bonnet theorem (GBT).

A study of an embedding class-I traversable wormhole in Galileon Gravity

In this article, we examine the possibility of the creation of a traversable wormhole geometry in Galileon Gravity (GG). In this gravity, the alternation of gravity is determined by an effective scalar field ϕ, treated as the Galileon field. From a mechanism perspective, GG is developed by covariantizing the decoupling Lagrangian of the DGP (Dvali-Gabadadze-Porrati) model. Now, to achieve our aim, gravitational field equations have been constructed corresponding to a line element, which represents a static and spherically symmetric spacetime. Next, we have modified these field equations in the context of a Morris-Thorne traversable wormhole spacetime. In particular, we have used the ‘Karmarkar condition’ to evaluate the wormhole solutions in a general sense. Further, for a better understanding of our obtained wormhole solutions, 2-dimensional and 3-dimensional diagrams have been displayed. Later, we scrutinized the possible creation of a traversable wormhole based on the essential requirements, that is, the infraction of energy conditions in the neighborhood of the throat region, especially the Null Energy Condition (NEC). For this purpose, we have discussed three cases like Case-I: without the necessity of dark energy (DE), Case-II: with support of phantom-like DE and Case-III: with the SFDM profile of a dark matter (DM) halo. Next, we have examined the hydrostatic equilibrium position corresponding to our obtained wormhole system in GG. Furthermore, to examine the small and sufficient quantity of exotic matter, the possible formation of a traversable wormhole has been explored by a volume integral quantifier. Lastly, we have shown the nature of active mass. Finally, we have concluded that traversable wormhole solutions can also be established in the presence of an effective scalar field without any essential support of exotic matter in the neighborhood of the throat region by GG.

The river model of gravitational collapse

We show that the transformation of a time-evolving spherically symmetric metric tensor into a Painlevé–Gullstrand–Lemaître form brings forth a few curious consequences. The time evolution describes a non-singular gravitational collapse, leading to a bounce and dispersal of all the clustered matter, or a wormhole geometry for certain initial conditions. The null convergence condition is violated only at the onset of bounce or the wormhole formation. As an example, the requirements to develop a Simpson–Visser wormhole/regular black-hole geometry is discussed. The solution can be regarded as a new time-evolving twin of sonic dumb holes found in analog gravity.

Rotating traversable wormhole geometries in the presence of three-form fields

In this work, we study the rotating wormhole geometries supported by a three-form field. We demonstrate for particular choices of parameters that it is possible for the matter fields threading the wormhole to satisfy the null and weak energy conditions throughout the spacetime, when the three-form field is present. In this case, the form field is interpreted as supporting the wormhole and the energy condition violation is restricted only to the 3-form fields. Thus, the three-form curvature terms, which may be interpreted as a gravitational fluid, sustain these wormhole geometries. Additionally, we also address the ergoregion of the solutions.

Effect of Rastall parameter on wormhole spacetime

In this paper, we investigate wormhole geometries within Rastall gravity. The field equations have been solved by assuming that spacetime admits conformal killing vectors. By assuming two separate scenarios, namely anisotropic and isotropic EoS, we are able to find the wormhole solutions. We note that the shape function for both the isotropic and anisotropic cases fails to meet the asymptotic flatness conditions, but both the solutions obey the flaring-out condition. The TOV equation has been used to verify the stability of wormhole solutions. Additionally, we discover that for the anisotropic case, the null energy condition is violated which is graphically analyzed and proves the presence of exotic matter. Finally, we use the volume integral quantifier to determine how much exotic matter is needed near the wormhole throat in the anisotropic scenario.

Ricci inverse gravity wormholes

The current study deals with the new wormhole solutions in the background of fourth order new modified Ricci inverse gravity. Two new classes of the wormhole solutions are analyzed by showing the valid region for the main part of wormhole geometry under the affect of involved parameters. The embedded diagrams for both generic shape functions are also presented, which are connecting upper and lower Universes. In order to check the existence of these wormhole solutions, energy conditions are included in the current analysis. In the maximum regions, all energy conditions are violated, which confirms the presence of exotic matter in the background of Ricci inverse gravity. Stability analysis for both wormhole solutions is explored within the scope of speed of sounds parameters. Conclusively, some highlights from this research confirm the realistic nature and viability of these wormhole solutions in Ricci inverse gravity.

Thin-shell wormholes with AdS black holes surrounded by Chaplygin dark fluid

In this paper, we inspect the stable geometry of thin-shell wormholes in the background of static spherically-symmetric AdS black holes solution bounded by dark fluid and Chaplygin-like equation of state [Formula: see text], where [Formula: see text] and [Formula: see text] denote the pressure and energy density that are related through positive constant [Formula: see text]. For this purpose, we consider the two equivalent copies of black holes and connected them at the hypersurface through cut and paste approach. Then, we employ the linearized radial perturbation to discuss the stability of the developed wormhole geometry by assuming variable equations of state. We obtain the maximum stable configuration for massive black holes for both barotropic and Chaplygin variable equations of state while for higher values of [Formula: see text], stable regions decrease. It is found that for every selection of physical parameters of black hole geometry with low intensity of Chaplygin dark fluid, we get the stable configuration of thin-shell wormholes.

Slow complexification

The fact that AdS black hole interior geometries are time-dependent presents two challenges: first, to holographic duality (the boundary matter tends to equilibrate, often very quickly), and, second, to the idea that wormholes can be traversable (the wormhole geometry is dynamic, and the wormhole is apt to collapse too quickly for traversal to be possible). As is well known, the first puzzle can be addressed by considering the quantum circuit complexity of the strongly coupled boundary matter, which can continue to grow long after equilibrium is established. We show that data from a phenomenological model of the Quark-Gluon Plasma indicate the existence of an upper bound on the rate of increase of the (specific) complexity, in agreement with a simple holographic model. We then point out that, in this model, this upper bound becomes stricter if angular momentum is added to the bulk black hole while fixing the temperature (at any value, so the black hole is not near-extremal). We show that the dual phenomenon, a dramatic slowing of the black hole interior dynamics at high specific angular momentum, also occurs. We conjecture that sufficiently slow complexification of the field theories dual to rotating black holes is associated with traversability of the bulk wormhole, when quantum effects are taken into account.

Construction of thin-shell around new wormhole solutions via solitonic quantum wave dark matter

In the present work, we study wormhole geometry in the framework of general relativity and explore the effects of quantum wave dark matter on the dynamical configuration of the shell around the wormhole. Aiming this aspect some specific shape functions have been checked for physically interesting results. Firstly, we develop the basic formalism and the respective field equations. Thereafter, we introduce quantum wave dark matter as an input for getting reasonable wormhole solutions where the physical interpretation of energy conditions within the average pressure scenario has been considered. The positive behavior of quantum wave dark matter density confirms the compatibility for four different parametric values of the model. We also use the specific values of boson mass parameter within the observational data of soliton core density, and soliton core radius for the SgrA∗ candidate. After this we have started to discuss the dynamics of the shell around the wormhole structure and observe the effects of quantum wave dark matter on the stability of the shell by using the equation of motion through radial linear perturbation. The outcomes of the investigation seem to provide several attractive attributes as well as futuristic possibilities to traditional wormhole studies.

New spherically symmetric wormhole solutions in f(Q)-gravity theory

In this study, we examine the new spherically symmetric wormhole solutions in modified symmetric teleparallel (f(Q)) gravity theory. Using the Morris-Thorne method, we construct traversable wormholes with a physically reasonable energy condition and investigate their stability under small perturbations. We discuss two wormhole geometries under the linear functional form of f(Q) with two distinct shape functions. Our results show that the violations of energy conditions in f(Q) gravity provide a viable framework for the study of wormholes. We analyze the properties of wormholes and their behavior under different conditions such as energy conditions, equilibrium conditions, and volume integral quantifiers to check the stability of wormholes. By using the anisotropy parameter, we observed that model-I is attractive in nature and model-II is attractive and repulsive both varying according to the value of r and constant parameters.

Thermodynamical properties of an ideal gas in a traversable wormhole

In this work, we analyze the thermodynamic properties of non-interacting particles under influence of the gravitational field of a traversable wormhole. In particular, we investigate how the thermodynamic quantities are affected by the Ellis wormhole geometry, considering three different regions to our study: asymptotically far, close to the throat, and at the throat. The thermodynamic quantities turn out to depend strongly on parameter that controls the wormhole throat radius. By varying it, there exist an expressive modification in the thermodynamic state quantities, exhibiting both usual matter and dark energy–like behaviors. Finally, the interactions are regarded to the energy density and it seems to indicate that it ”cures” the dark energy–like features.

Physical characteristics of wormhole geometries under different EoS in the context of Rastall gravity

This paper investigates the characteristics of wormhole solutions within the framework of Rastall gravity. First, we derived the shape functions using two different equations of state (EoS). Then we examined the essential characteristics of the shape function for wormholes and the behavior of energy conditions. The present investigation based on the EoS produces wormhole solutions valid for negative values of μ or Υ, where μ=κΥ is a dimensionless parameter and Υ denotes a Rastall parameter. Furthermore, the Rastall parameter Υ plays a vital role in the stability conditions and geometric properties of a wormhole. The volume integral quantifier (V IQ) is also discussed, which gives the idea of the amount of exotic matter required near the wormhole throat. The conclusion shows that our solutions derived using both EoS in Rastall gravity are physically feasible.

Traversable wormholes in Rastall-Rainbow gravity

In this paper, we investigate the existence of asymptotically flat wormhole geometries within the framework of Rastall-Rainbow modified gravity, a synthesis of two distinct theoretical models: Rastall theory and the Rainbow description. Our study uncovers that, when considering specific combinations of free parameters and equations of state, the emergence of static and spherically symmetric wormholes is not feasible within a zero-tidal-force context. By considering the subset of viable solutions, we conduct a rigorous assessment of their stability through adiabatic sound velocity analysis and scrutinize their compliance with the Weak Energy Condition (WEC). Our inquiry provides insights into how the interplay between Rastall parameters and Rainbow functions may alleviate violations of energy conditions in these modified gravity scenarios.

Study of viable charged wormhole solutions in [formula omitted] theory

In this paper, we investigate how charge and modified terms affect the viability and stability of traversable wormhole geometry in the framework of f(R,G) theory, where R is the Ricci scalar and G is the Gauss–Bonnet term. For this purpose, we develop a shape function through the Karmarkar condition to examine the wormhole geometry. The resulting shape function satisfies all the necessary conditions and establishes a connection between the asymptotically flat regions of the spacetime. The behavior of energy conditions and sound speed is checked in the presence of higher-order curvature terms and electromagnetic field to analyze the existence of stable traversable wormhole geometry. It is found that the traversable wormhole solutions are viable and stable in this modified theory.

Possible existence of traversable wormhole in Finsler–Randers geometry

In the present article, we have explored the possible existence of a traversable wormhole in the framework of Finsler–Randers (F–R) geometry. In order to achieve this goal, first, we have constructed gravitational field equations for static, spherically symmetric spacetime with anisotropic fluid distribution in F–R geometry. Next, we have written the deduced form of field equations in the background of Morris–Thorne wormhole geometry. To visualize the shape of the wormhole, we have selected exponential shape function b(r)=frac{r}{expleft( eta left( frac{r}{r_{0}} - 1right) right) } with the constant parameter eta and the throat radius r_{0} and depicted two-dimensional and three-dimensional embedding diagrams corresponding to some considered values of eta and r_{0}. Moreover, all essential requirements to build a wormhole shape have been examined for the reported shape function. Next, We have analyzed wormhole configuration for three cases (I, II, III) corresponding to three selected redshift functions. Furthermore, each case is analyzed by dividing it into two models such as (i) Model-1 (for general anisotropic EoS p_{t}=chi p_{r}) and (ii) Model-2 (for linear phantom-like EoS p_{r} + omega rho =0). In each model of three cases, we have verified the validity of the wormhole solution in F–R geometry by considering null, weak, strong and dominant energy conditions. Also, the total amount of averaged NEC-violating matter near the wormhole throat has been analyzed by computing volume integral quantifier.

Quantum corrected charged thin-shell wormholes surrounded by quintessence

In this manuscript, we inspect the stable geometry of thin-shell wormholes in the framework of static, spherically-symmetric quantum corrected charged black hole solution bounded by quintessence. In this regard, we develop thin-shell wormholes from two equivalent copies of black hole solutions through the cut and paste approach. Then, we employ the linearized radial perturbation to discuss the stability of the developed wormhole geometry by assuming variable equations of state. We obtain the maximum stable configuration for massive black holes for both barotropic and Chaplygin variables equations of state. It is found that the quantum correction affects the stability of thin-shell wormholes and the presence of charge over the geometry of black holes enhances the stable configuration of thin-shell wormholes.

New wormhole model with quasi-periodic oscillations exhibiting conformal motion in gravity

This analysis explores the new wormhole (WH) solution in the background of teleparallel gravity with minimal matter coupling. To complete this study, we consider the conformal symmetry with non-zero Killing vectors. The exact shape function is computed by considering the linear equation of state with the phantom regime. The energy conditions are investigated for the calculated shape function with the equation of state parameter. The presence of exotic matter is confirmed due to the violation of the null energy condition. The current study also explores the physical properties of the epicyclic frequencies with quasi-periodic oscillations. In the astrophysical, epicyclic frequencies are extensively employed to explore the self-gravitating system. It is concluded that a stable WH solution is acceptable for WH geometry.