New results on charged compact boson stars

Abstract

In this work we present some new results which we have obtained in a study of the phase diagram of charged compact boson stars in the theory involving massive complex scalar fields coupled to the U(1) gauge field and gravity in a conical potential in the presence of a cosmological constant Λ which we treat as a free parameter taking positive and negative values and thereby allowing us to study the theory in the de Sitter and Anti de Sitter spaces respectively. In our studies, we obtain four bifurcation points (possibility of more bifurcation points being not ruled out) in the de Sitter region. We present a detailed discussion of the various regions in our phase diagram with respect to four bifurcation points. Our theory is seen to have rich physics in a particular domain for positive values of Λ which is consistent with the accelerated expansion of the universe.Introduced long ago [1][2][3], boson stars represent localized self-gravitating solutions studied vary widely in the literature [4][5][6][7][8][9][10][11][12][13][14][15][16][17][18][19][20][21][22][23]. Such theories are being considered in the presence of positive [14][15][16] as well as negative [17][18][19][20] values of the cosmological constant Λ. The theories with positive values of Λ (corresponding to the de Sitter (dS) space) are relevant from observational point of view as they describe a more realistic description of the compact stars in the universe since all the observations seem to indicate the existence of a positive cosmological constant. Such theories are also being used to model the dark energy of the universe. However, the theories with negative values of Λ (corresponding to the Anti de Sitter (AdS) space) are meaningful in the context of AdS/CFT correspondence [24][25][26].In fact, cosmological constant, the value of the energy density of the vacuum of space is the simplest form of dark energy and it provides a good fit to many cosmological observations. A positive vacuum energy density resulting from a positive cosmological constant (implying a negative) pressure gives an accelerated expansion of the universe consistent with the observations. Our theory is seen to have rich physics in a particular domain for positive values of Λ.have studied In a recent paper [15], we have studied the boson stars and boson shells in a theory of complex scalar field coupled to U (1) gauge field A µ and the gravity in the presence of a fixed positive cosmological constant Λ (i.e. in the de Sitter space). In the present work we study this theory of complex scalar field coupled to U (1) gauge field A µ and the gravity in the presence of a potential: V (|Φ|) := (m 2 |φ| 2 + λ|φ|) (with m and λ are constant parameters) and a cosmological constant Λ which we treat as a free parameter and which takes positive as well as negative values and thereby allowing us to study the theory in the dS as well as in the AdS space. We investigate * sanjeev.kumar.ka@gmail.com † ushakulsh@gmail.com, ushakuls@iastate.edu ‡ dskulsh@gmail.com, dayakuls@iastate.edu the properties...

Charged compact boson stars and shells in the presence of a cosmological constant

“…Boson stars and boson shells representing the localized self-gravitating solutions were introduced long ago [1-3] and they have been studied vary widely in the literature . Such theories are being considered in the presence of positive [14][15][16][17] as well as negative [15,[17][18][19][20][21] values of the cosmological constant Λ. The theories with positive values of Λ (corresponding to the de Sitter (dS) space) are relevant from observational point of view as they describe a more realistic description of the compact stars in the universe since all the observations seem to indicate the existence of a positive cosmological constant.…”

Post-Newtonian templates for binary black-hole inspirals: the effect of the horizon fluxes and the secular change in the black-hole masses and spins

“…The impact of BH absorption for parameter-estimate predictions for LIGO-type and LISAtype detectors could be investigated in future work. The issue of the corresponding systematic biases in (PN) template families due to the effect of BH absorption would be also a relevant extension of our work; systematic errors in GW observations was already discussed in the context of neutron-star binaries [104,105,106] as well as BBHs [27,107,108].…”

Phase diagrams of charged compact boson stars

“…Here compact is meant to describe a solution whose scalar field vanishes outside a compact region of space identically. Thus while ordinary boson stars do not feature sharp boundaries, since their scalar field exhibits only an exponential fall-off, in compact boson stars, the scalar field is completely confined to a finite region of space [27][28][29][30][31][32][33][34][35].…”

“…Studies of the charged compact boson stars in a theory involving a massive complex scalar field with a conical potential coupled to a U(1) gauge field and gravity were undertaken in Refs. [31,32] and [33,34]. In this work, the 2D and 3D phase diagrams were investigated in rather great detail, and multiple bifurcation points showing the presence of rather rich physics were obtained for a particular range of the parameters of the theory.…”