Gravity localization on hybrid branes

Abstract

This work deals with gravity localization on codimension-1 brane worlds engendered by compacton-like kinks, the so-called hybrid branes. In such scenarios, the thin brane behaviour is manifested when the extra dimension is outside the compact domain, where the energy density is non-trivial, instead of asymptotically as in the usual thick brane models. The zero mode is trapped in the brane, as required. The massive modes, although are not localized in the brane, have important phenomenological implications such as corrections to the Newton's law. We study such corrections in the usual thick domain wall and in the hybrid brane scenarios. By means of suitable numerical methods, we attain the mass spectrum for the graviton and the corresponding wavefunctions. The spectra possess the usual linearly increasing behaviour from the Kaluza-Klein theories. Further, we show that the 4D gravitational force is slightly increased at short distances. The first eigenstate contributes highly for the correction to the Newton's law. The subsequent normalized solutions have diminishing contributions. Moreover, we find out that the phenomenology of the hybrid brane is not different from the usual thick domain wall. The use of numerical techniques for solving the equations of the massive modes is useful for matching possible phenomenological measurements in the gravitational law as a probe to warped extra dimensions.Comment: 15 pages, 11 figure

Thick braneworld model in nonmetricity formulation of general relativity and its stability

“…Thus, it is more realistic to investigate the thick braneworld models, where the brane is generated by one or more background scalar fields and the energy density of the brane is a smooth function of the extra dimension [23][24][25][26][27][28][29][30][31][32][33][34][35][36][37][38][39][40] instead of a Dirac delta function in the thin braneworld models. In the thick braneworld models, although the size of the extra dimension is infinity, the matter fields corresponding to the standard model are confined on the brane [41][42][43][44][45][46][47] and the localized graviton zero mode produces the four-dimensional Newtonian potential [48][49][50][51][52][53][54], which are two key points reconstructing our effective fourdimensional world. One can see Ref.…”

Hybrid Bloch brane

“…In the limit where n is very large, the kink-like solution tends to become compacted to a finite region of space, into a compact interval, while the lump-like solution remains decaying asymptotically. When the extra dimension is outside the compact interval, there arises a thin brane behavior, identified by the non-trivial behavior of the energy density, while a thick brane is displayed inside the compact space [27][28][29]. This is the reason to suggest that the compact-like behavior leads to the hybrid brane, as was originally suggested in [27] in the case of a single field.…”

“…[27] proposed a route to smoothly go from kinks to compactons, leading to a braneworld formulation generated by compact-like defects; it occasioned a hybrid brane symmetric configuration. Phenomenological implications of this scenario are discussed in [28], and in Ref. [29] these ideas are extended to the consideration of models that support asymmetric compact-like structures, in a way that leads to an asymmetric hybrid brane profile.…”

Novel thick brane solutions with U(1) symmetry breaking

“…By plugging Eqs. (20) into Eqs. (9) and (10), the superpotential of φ and ψ (or −ψ) fields are given by:…”

“…The exact shape of the structures depend essentially on the a e-mail: marziyeh.peyravi@stu-mail.um.ac.ir b e-mail: n_riazi@sbu.ac.ir c e-mail: fslobo@fc.ul.pt (corresponding author) physics, spacetime dimensions, symmetry breaking and the topology of the vacua. Based on the literature, at least three classes of models exist that support these kink-like defects [11][12][13][14][15][16][17][18][19][20]. The first class deals with a single real scalar field, which leads to structureless topological solutions, such as the sine-Gordon and φ 4 models.…”