Possible existence of wormholes in the central regions of halos

Abstract: An earlier study [Rahaman et al. (2014) & Kuhfittig (2014)] has demonstrated the possible existence of wormholes in the outer regions of the galactic halo, based on the Navarro-Frenk-White (NFW) density profile. This paper uses the Universal Rotation Curve (URC) dark matter model to obtain analogous results for the central parts of the halo. This result is an important compliment to the earlier result, thereby confirming the possible existence of wormholes in most of the spiral galaxies.

• The paper investigates the theoretical possibility of wormholes existing in the central regions of galactic halos using the URC dark matter model.
• The study finds that the URC density profile satisfies the necessary conditions, such as energy condition violation and flare-out, for supporting wormholes in the inner halo regions.
• This research suggests that the dark matter within galactic halos could potentially provide the exotic matter required for such wormholes, encouraging future observational efforts.

Possible Existence of Wormholes in the Central Regions of Halos

The paper investigates the theoretical possibility of wormholes existing in the central regions of galactic halos, expanding on previous work that proposed wormholes might exist in the outer regions based on the Navarro-Frenk-White (NFW) density profile. This study specifically leverages the Universal Rotation Curve (URC) dark matter model to examine the inner halo regions, yielding results that potentially confirm the existence of wormholes in the majority of spiral galaxies.

The research applies the Morris-Thorne framework to describe a spacetime conducive to wormholes. Two critical functions—the redshift function $f(r)$ and shape function $b(r)$—characterize this framework. The redshift function must remain finite to avoid event horizons, and the shape function must satisfy the flare-out condition to support a traversable wormhole. These conditions inherently require violations of the null energy condition (NEC), stipulating $\rho + p_r < 0$, with $\rho$ being energy density and $p_r$ denoting radial pressure.

To explore wormhole existence in the inner halo, the authors consider the URC density profile: $\rho(r) = \frac{\rho_0 r_0^3}{(r+r_0)(r^2+r_0^2)},$ where $r_0$ is the core radius, and $\rho_0$ is the effective core density. This study focuses on modeling the central halo regions using these parameters, contrasting with the previously considered NFW profile known for discrepancies in central velocity predictions.

The authors derive key equations linking the redshift and shape functions with the URC model and use these to calculate the radial and lateral pressures. Through a detailed examination of the derived solution, they find the critical conditions for wormholes, such as throat size and energy condition violations, are met for most spiral galaxy profiles.

For empirical justification, the study also evaluates the behavior of the model using data from the Milky Way, concluding that the existence of dark matter in these halos could feasibly provide the required exotic matter to sustain wormholes. With $b(r_0)\approx 1.74\times 10^{-6}$ in the Milky Way context, the flare-out condition is satisfied, substantiating the theoretical model with plausible astrophysical scenarios.

While the research refrains from proposing methods to create or observe such wormholes, it serves as a theoretical incentive for further empirical investigation and modeling refinement. The potential confirmation of wormholes relies on recognizing the distinctive rotation curves observable in spiral galaxies, which could guide future direct or indirect observational efforts, such as gravitational lensing studies.

The implications of the study suggest novel avenues for exploring cosmic structures within relativistic frameworks. It provides insight into the fundamental understanding of dark matter and extragalactic astrophysics. In terms of future developments, further computational simulations and observational scrutiny could either reinforce or challenge the assumptions underlying this theoretical framework.