ترغب بنشر مسار تعليمي؟ اضغط هنا

A simple traversable wormhole violating energy conditions only at the Planck scale

163   0   0.0 ( 0 )
 نشر من قبل Hideki Maeda
 تاريخ النشر 2021
  مجال البحث فيزياء
والبحث باللغة English
 تأليف Hideki Maeda




اسأل ChatGPT حول البحث

We present a simple static spacetime which describes a spherically symmetric traversable wormhole characterized by a length parameter $l$ and reduces to Minkowski in the limit $lto 0$. The wormhole connects two distinct asymptotically flat regions with vanishing ADM mass and the areal radius of its throat is exactly $l$. All the standard energy conditions are respected outside the proper radial distance approximately $1.60l$ from the wormhole throat. If $l$ is identified as the Planck length $l_{rm p}$, the total amount of the negative energy supporting this wormhole is only $Esimeq -2.65m_{rm p}c^2$, which is the rest mass energy of about $-5.77times 10^{-5}{rm g}$.



قيم البحث

اقرأ أيضاً

A possible candidate for the present accelerated expansion of the Universe is phantom energy, which possesses an equation of state of the form $omegaequiv p/rho<-1$, consequently violating the null energy condition. As this is the fundamental ingredi ent to sustain traversable wormholes, this cosmic fluid presents us with a natural scenario for the existence of these exotic geometries. In this context, we shall construct phantom wormhole geometries by matching an interior wormhole solution, governed by the phantom energy equation of state, to an exterior vacuum at a junction interface. Several physical properties and characteristics of these solutions are further investigated. The dynamical stability of the transition layer of these phantom wormholes to linearized spherically symmetric radial perturbations about static equilibrium solutions is also explored. It is found that the respective stable equilibrium configurations may be increased by strategically varying the wormhole throat radius.
We study a traversable wormhole originated by a transformation over the 4D Dymnikova metric which describes analytic Black-Holes (BH). By using a transformation of coordinates which is adapted from the used in the Einstein-Rosen bridge, we study a sp ecific family of geodesics in which a test particle with non-zero electric charge induces an effective magnetic monopole, that is perceived by observers outside the wormhole. Because the Riemannian geometry cannot explain the presence of magnetic monopoles, then we propose a torsional geometry in order to explore the possibility that magnetic monopoles can be geometrically induced. We obtain an expression that relates torsion and magnetic fields jointly with a Dirac-like expression for magnetic and electric charges, such that torsion makes possible define a fundamental length that provides a magnetic field and a spacetime discretization.
The current interests in the universe motivate us to go beyond Einsteins General theory of relativity. One of the interesting proposals comes from a new class of teleparallel gravity named symmetric teleparallel gravity, i.e., $f(Q)$ gravity, where t he non-metricity term $Q$ is accountable for fundamental interaction. These alternative modified theories of gravitys vital role are to deal with the recent interests and to present a realistic cosmological model. This manuscripts main objective is to study the traversable wormhole geometries in $f(Q)$ gravity. We construct the wormhole geometries for three cases: (i) by assuming a relation between the radial and lateral pressure, (ii) considering phantom energy equation of state (EoS), and (iii) for a specific shape function in the fundamental interaction of gravity (i.e. for linear form of $f(Q)$). Besides, we discuss two wormhole geometries for a general case of $f(Q)$ with two specific shape functions. Then, we discuss the viability of shape functions and the stability analysis of the wormhole solutions for each case. We have found that the null energy condition (NEC) violates each wormhole model which concluded that our outcomes are realistic and stable. Finally, we discuss the embedding diagrams and volume integral quantifier to have a complete view of wormhole geometries.
We explore the possibility that well known properties of the parity operator, such as its idempotency and unitarity, might break down at the Planck scale. Parity might then do more than just swap right and left polarized states and reverse the sign o f spatial momentum ${bf k}$: it might generate superpositions of right and left handed states, as well as mix momenta of different magnitudes. We lay down the general formalism, but also consider the concrete case of the Planck scale kinematics governed by $kappa$-Poincare symmetries, where some of the general features highlighted appear explicitly. We explore some of the observational implications for cosmological fluctuations. Different power spectra for right handed and left handed tensor modes might actually be a manifestation of deformed parity symmetry at the Planck scale. Moreover, scale-invariance and parity symmetry appear deeply interconnected.
100 - Alex Simpson , Matt Visser 2018
So-called regular black holes are a topic currently of considerable interest in the general relativity and astrophysics communities. Herein we investigate a particularly interesting regular black hole spacetime described by the line element [ ds^{2}= -left(1-frac{2m}{sqrt{r^{2}+a^{2}}}right)dt^{2}+frac{dr^{2}}{1-frac{2m}{sqrt{r^{2}+a^{2}}}} +left(r^{2}+a^{2}right)left(dtheta^{2}+sin^{2}theta ;dphi^{2}right). ] This spacetime neatly interpolates between the standard Schwarzschild black hole and the Morris-Thorne traversable wormhole; at intermediate stages passing through a black-bounce (into a future incarnation of the universe), an extremal null-bounce (into a future incarnation of the universe), and a traversable wormhole. As long as the parameter $a$ is non-zero the geometry is everywhere regular, so one has a somewhat unusual form of regular black hole, where the origin $r=0$ can be either spacelike, null, or timelike. Thus this spacetime generalizes and broadens the class of regular black holes beyond those usually considered.
التعليقات
جاري جلب التعليقات جاري جلب التعليقات
سجل دخول لتتمكن من متابعة معايير البحث التي قمت باختيارها
mircosoft-partner

هل ترغب بارسال اشعارات عن اخر التحديثات في شمرا-اكاديميا