Related papers: Tachyon Monopole
The Einstein-Friedmann Universe as whole quantum object can be treated as bosonic string mass groundstate, called a tachyon, having negative mass square and a speed more than the speed of light. I present a brief review of results obtained…
We investigate the space-time of a global monopole in a five dimensional space-time in presence of the cosmological term. Also the gravitational properties of the monopole solution are discussed.
A new solution to the coupled gravitational and scalar field equations for a condensed boson field is found in Newtonian approximation. The solution is axially symmetric, but not spherically symmetric. For N particles the mass of the object…
We perform a thorough phase-plane analysis of the flow defined by the equations of motion of a FRW universe filled with a tachyonic fluid plus a barotropic one. The tachyon potential is assumed to be of inverse square form, thus allowing…
We study exact, analytic, static, spherically symmetric, four-dimensional solutions of minimally coupled Einstein-scalar gravity, sourced by a scalar field whose profile has the form of the sine-Gordon soliton. We present a horizonless,…
We consider the space-time metric generated by a global monopole in an extension of General Relativity (GR) of the form $f(\mathcal{R})=\mathcal{R}-\lambda \mathcal{R}^2$. The theory is formulated in the metric-affine (or Palatini)…
We study the dynamics of the scalar tensor cosmological model in the presence of tachyon field. In an alternative approach, in two exponential and power law form of the scalar field functions in the model, field equations are solved by…
Dipole fields are common in electromagnetism and may be viewed as the result of a positive and negative charge (or pole) which are close together. A dipole field in gravity is not expected to exist because negative mass has never been…
We study the role of rolling tachyons in the cosmological model with dilatonic gravity. In the string frame, flat space solutions of both initial-stage and late-time are obtained in closed form. In the Einstein frame, we show that every…
We study the general properties of attractors in a cosmological model with tachyonic potential and a scalar field non-minimally coupled to matter. A general analytic formulation is given to derive fixed points with a discussion on their…
We study the condensation of closed string tachyons as a time-dependent process. In particular, we study tachyons whose wave functions are either space-filling or localized in a compact space, and whose masses are small in string units; our…
A general procedure to find static and axially symmetric, interior solutions to the Einstein equations is presented. All the so obtained solutions, verify the energy conditions for a wide range of values of the parameters, and match…
We use local counterterm prescriptions for asymptotically flat space to compute the action and conserved quantities in five-dimensional Kaluza-Klein theories. As an application of these prescriptions we compute the mass of the Kaluza-Klein…
The dynamical behavior of tachyon field with an inverse potential is investigated in loop quantum cosmology. It reveals that the late time behavior of tachyon field with this potential leads to a power-law expansion. In addition, an…
We study a set of static solutions of the Einstein equations in presence of a massless scalar field and establish their connection to the Kantowski-Sachs cosmological solutions based on some kind of duality transformations. The physical…
First we review some of the attempts made to find exact spherically symmetric solutions of Einstein field equations in the presence of scalar fields .Wyman solution in both static and non static scalar field is discussed briefly and it is…
We study the Einstein-Chern-Simons gravity coupled to Yang-Mills-Higgs theory in three dimensional Euclidean space with cosmological constant. The classical equations reduce to Bogomol'nyi type first order equations in curved space. There…
We investigate the spacetime-dependent condensation of the tachyon in effective field theories. Previous work identified singularities in the field which appear in finite time: infinite gradients at the kinks, and (in the eikonal…
Using the quasi-Maxwell form of the vacuum Einstein equations and demanding the presence of a cylindrically symmetric radial gravomagnetic field, we find the solution to the Einstein equations which represents the gravity field of a line…
The gluon spin coupling to a Gaussian correlated background gauge field induces an effective tachyonic gluon mass. It is momentum dependent and vanishes in the UV only like 1/p^2. In the IR, we obtain stabilization through a positive…