We investigate the mixing between Kaluza-Klein (KK) modes for a bulk U(1) gauge field within braneworld models. By demanding orthonormality and completeness for the KK basis functions, we demonstrate that the decoupling of mixed sectors, specifically of the vector-scalar and scalar-scalar types, imposes stringent constraints on the warp factors of codimension-d (d>1) backgrounds. We show that the gauge invariance of the four-dimensional effective action is preserved despite such mixing, manifesting as an intrinsic property of the massive vector KK sector. However, the generic presence of vector-scalar mixing fundamentally alters the absorption mechanism of the scalar modes, dynamically shifting the physical masses of the vector KK modes away from their unperturbed eigenvalues. In (4+2)-dimensional models, the existence of two distinct scalar sectors significantly enriches the mixing dynamics. As the massive vectors absorb only specific linear combinations of these scalars, a residual set of massive scalar KK modes persists as physical degrees of freedom.
The Kaluza-Klein (KK) modes of a massive scalar field on a 3-brane embedded in six dimensional multiply warped spacetime are determined. Due to the presence of warping along both the extra dimensions the KK mass spectrum splits into two closely spaced branches which is a distinct feature of this model compared to the five dimensional Randall-Sundrum model. This new cluster of the KK mode spectrum is expected to have interesting phenomenological implications for the upcoming collider experiments. Such a scenario may also be extended for even larger number of orbifolded extra dimensions.
We extend the recently proposed Kerr/CFT correspondence to examine the dual conformal field theory of Kaluza-Klein black hole. For the extremal Kaluza-Klein black hole, the central charge and temperature of the dual conformal field are calculated, and the microscopic entropy calculated by using Cardy formula agrees with the Bekenstein-Hawking entropy of extremal Kaluza-Klein black hole. For the non-extremal case, we investigate the hidden conformal symmetry of Kaluza-Klein black hole by studying the near-region wave equation of a neutral massless scalar field, and find the left and right tempe…
We perform a numerical study of the four-dimensional spin-2 Kaluza-Klein spectrum of supersymmetric AdS$_4\times S^2(\mathcal{B}_4)$ vacua and show that they do not exhibit scale separation. Our methods are generally applicable to similar problems where the compactification geometry is not known analytically, hence an analytic treatment of the spectrum of Kaluza-Klein masses is not available.
We address the question of whether or not fermions with twisted periodicity condition suppress the semiclassical decay of M^4xS^1 Kaluza--Klein vacuum. We consider a toy (1+1)-dimensional model with twisted fermions in cigar-shaped Euclidean background geometry and calculate the fermion determinant. We find that contrary to expectations, the determinant is finite. We consider this as an indication that twisted fermions do not stabilize the Kaluza--Klein vacuum.
The dynamics of chiral p-forms can be captured by a lower-dimensional parity-violating action motivated by a Kaluza-Klein reduction on a circle. The massless modes are (p-1)-forms with standard kinetic terms and Chern-Simons couplings to the Kaluza-Klein vector of the background metric. The massive modes are p-forms charged under the Kaluza-Klein vector and admit parity-odd first-order kinetic terms. Gauge invariance is implemented by a Stueckelberg-like mechanism using (p-1)-forms. A Chern-Simons term for the Kaluza-Klein vector is generated at one loop by massive p-form modes. These findings…
In this contribution we study the Klein-Gordon oscillator on the curved background within the Kaluza-Klein theory. The problem of interaction between particles coupled harmonically with a topological defects in Kaluza-Klein theory is studied. We consider a series of topological defects, that treat the Klein-Gordon oscillator coupled to this background and find the energy levels and corresponding eigenfunctions in these cases. We show that the energy levels depend on the global parameters characterizing these spacetimes. We also investigate a quantum particle described by the Klein-Gordon oscil…
We consider a generalised two brane Randall-Sundrum model with non-zero cosmological constant on the visible TeV brane. Massive Kaluza-Klein modes for various bulk fields namely graviton, gauge field and antisymmetric second rank Kalb-Ramond field in a such generalized Randall-Sundrum scenario are determined. The masses for the Kaluza-Klein excitations of different bulk fields are found to depend on the brane cosmological constant indicating interesting consequences in warped brane particle phenomenology
本文描述了具有两个紧致方向的D+1维纯Einstein理论中新的泡衰变。通过对带电黑洞解的解析延拓构造了瞬子解。我们证明了瞬子描述了具有非零环面倾斜参数的卡鲁扎-克莱因真空M^{D-1} x T^2的衰变。衰变是由一个空无一物的气泡产生的，它会随着时间的推移而膨胀。我们计算的瞬子作用，这表明，这个卡鲁扎-克莱因真空变得更加稳定的环面倾斜参数的增加。作为应用，我们考虑了导致0A/0 B型弦论的M-理论环面紧化的衰变。
We perform a Kaluza-Klein inspired rewriting of double field theory by splitting the coordinates into `compact' and `non-compact' directions. There is no truncation of the compact coordinates or their duals, and so this formulation is manifestly O(d,d) invariant, with d the number of compact directions. The action can serve as starting point for arbitrary Kaluza-Klein ansaetze. For a torus background the theory describes the full tower of Kaluza-Klein modes or, in the dual frame, of the winding modes. The Kaluza-Klein vector is a gauge field for the duality-covariantized Courant bracket algebr…
We construct new exact solutions to 5D Einstein-Maxwell equations describing sequences of Kaluza-Klein bubbles and dipole black rings. The solutions are generated by 2-soliton transformations from vacuum black ring - bubble sequences. The properties of the solutions are investigated. We also derive the Smarr-like relations and the mass and tension first laws in the general case for such configurations of Kaluza-Klein bubbles and dipole black rings. The novel moment is the appearance of the magnetic flux in the Smarr-like relations and the first laws.
Remembering the foundational contributions of Peter Freund to supergravity, and especially to the problems of dimensional compactification, reduction is considered with a non-compact space transverse to the lower dimensional theory. The known problem of a continuum of Kaluza-Klein states is avoided here by the occurrence of a mass gap between a single normalizable zero-eigenvalue transverse wavefunction and the edge of the transverse state continuum. This style of reduction does not yield a formally consistent truncation to the lower dimensional theory, so developing the lower-dimensional effe…
The non-Abelian Kaluza-Klein unification of gravitation with gauge fields theory is reformulated, with the inclusion of a massive spin-2 field defined by the extrinsic curvature. The internal space is non-compact, characterized by the group of rotations of vectors orthogonal to the space-time. The non-compactness of the internal space warrants the solution of the fermion chirality problem of the original Kaluza-Klein theory and makes it closer to the more recent Brane World paradigm, in special to the so called DGP model. However, the access of gravitation to the extra dimensions is defined by…
We analyze the effective field equations of the Randall-Sundrum braneworld coupled with a Klein-Gordon scalar field through the minimal geometric deformation decoupling method (MGD-decoupling). We introduce two different ways to apply the MGD-decoupling method to obtain new solutions for this enlarged system. We also compare the behavior of the new solutions with those obtained directly from the Randall-Sumdrum braneworld without coupling to the scalar field.
In this note we present a closed expression for the space-time effective action for all bosonic fields (massless and massive) obtained from the compactification of gravity or supergravity theories (such as type II or eleven-dimensional supergravities) from $D$ to $d$ space-time dimensions.
We construct a new exact solution to the 5D Einstein equations describing rotating black ring with a single angular momentum surrounded by two Kaluza-Klein bubbles. The solution is generated by 2-soliton Bäcklund transformation. Its physical properties are computed and analyzed. The corresponding static solution, the rotating black string and the boosted black string are reproduced as limits.
We examine the challenge of viewing all the fields in supergravity as arising from a Kaluza-Klein like dimensional reduction of some higher-dimensional theory. This gives rise to what is known as exceptional field theory or double field theory. A particular emphasis is placed on following the Kaluza-Klein intuition leading to the identification of charged states and a reinterpretation of the central charges. We further give a description of the novel extended geometry as a generalised phase space and the relationship to string and M-theory theory and the notion of quantization
In this work the gravitational Kaluza-Klein (KK) modes are analysed on string-like braneworlds in six dimensions, namely the thin string-like Gherghetta-Shaposhnikov (GS) and the thick string-cigar model. We find a new massless mode in both modes satisfying the respective Schroedinger equation. By means of numerical analysis for both models, a complete graviton spectrum and eigenfunctions is attained. Besides the linear regime, the KK spectrum exhibits a decreasing behavior with an asymmetric mass gap with respect to the massless mode. The discontinuity is bigger in the GS model, and it is inv…
We study the spin 1/2 and spin 3/2 fermion fields in a thick braneworld scenario in six dimensions called string-cigar model. This smooth string-like model has a source that satisfies the dominant energy condition and undergoes a Ricci flow. We propose a new coupling for the fermions with a background gauge field which allows a smooth and normalized massless mode in the brane with positive tension. By numerical methods the mass spectrum and the massive eigenfunctions are obtained. The Kaluza-Klein massive tower exhibits the usual increasing pattern and, in this scenario, the coupling term does…
The stability of squashed Kaluza-Klein black holes is studied. The squashed Kaluza-Klein black hole looks like five dimensional black hole in the vicinity of horizon and four dimensional Minkowski spacetime with a circle at infinity. In this sense, squashed Kaluza-Klein black holes can be regarded as black holes in the Kaluza-Klein spacetimes. Using the symmetry of squashed Kaluza-Klein black holes, $SU(2)\times U(1)\simeq U(2)$, we obtain master equations for a part of the metric perturbations relevant to the stability. The analysis based on the master equations gives a strong evidence for th…
