High Energy Physics Theory

In this paper we find analytical solutions for the scalar and gauge fields in the Freedman-Robertson-Walker multiply warped braneworld scenario. With this we find the precise mass spectra for these fields. We compare these spectra with that previously found in the literature for the static case.

The relativistic wave equations determine the dynamics of quantum fields in the context of quantum field theory. One of the conventional tools for dealing with the relativistic bound-state problem is the Klein-Fock-Gordon equation. In this work, using a developed scheme, we present how to surmount the centrifugal part and solve the modified Klein-Fock-Gordon equation for the linear combination of Hulthén and Yukawa potentials. In particular, we show that the relativistic energy eigenvalues and corresponding radial wave functions are obtained from supersymmetric quantum mechanics by applying the shape invariance concept. Here, both scalar potential conditions, which are whether equal and non-equal to vector potential, are considered in the calculation. The energy levels and corresponding normalized eigenfunctions are represented as a recursion relation regarding the Jacobi polynomials for arbitrarylstates. Beyond that, a closed-form of the normalization constant of the wave functions is found. Furthermore, we state that the energy eigenvalues are quite sensitive with potential parameters for the quantum states. The non-relativistic and relativistic results obtained within SUSY QM overlap entirely with the results obtained by ordinary quantum mechanics, and it displays that the mathematical implementation of SUSY quantum mechanics is quite perfect.

We consider the off-shell momentum space Green's functions in closed superstring field theory. Recently in arXiv:1810.07197, the off-shell Green's functions -- after explicitly removing contributions of massless states -- have been shown to be analytic on a domain (to be called the LES domain) in complex external momenta variables. Analyticity of off-shell Green's functions in local QFTs without massless states in the primitive domain is a well-known result. Using complex Lorentz transformations and Bochner's theorem allow to extend the LES domain to a larger subset of the primitive domain. For the 2-, 3- and 4-point functions, the full primitive domain is recovered. For the 5-point function, we are not able to obtain the full primitive domain analytically, only a large part of it is recovered. While this problem arises also for higher-point functions, it is expected to be only a technical issue.

The Chern-Simons magnetohydrodynamics (CSMHD) is introduced using a Maxwell-Chern-Simons (MCS) Lagrangian including an axion-like field?. The MCS equation of motion derived from this Lagrangian consists of a modified current, including a chiral magnetic (CM) and an anomalous Hall (AH) current, in addition to the ordinary Ohm current of resistive magnetohydrodynamics (MHD). The former consists of an axial chemical potential, which is given in terms of the temporal comoving derivative of?, and the latter arises from the spatial gradient of?. As it turns out, the existence of the axial chemical potential is a nonequilibrium effect that plays no role in the linear stability analysis, whereas the AH current arises as in the first-order linear perturbation of the thermal equilibrium. We analyze the linear stability and causality of the CSMHD in a resistive and chiral medium. We show that the Alfven modes propagating sufficiently close to the direction of the magnetic field are unstable but causal. They are also accompanied by a genuine nonhydro mode. A stable mode in a particular direction can correspond to an unstable mode propagating in the exact opposite direction. The AH instability is a manifestation of a breakdown of the parity. A numerical analysis of the phase velocity confirms these results.

Recently it was shown that the scaling dimension of the operator?ninλ(????)2theory may be computed semi-classically at the Wilson-Fisher fixed point ind=4?��?, for generic values ofλnand this was verified to two loop order in perturbation theory at leading and sub-leadingn. In subsequent work, this result was generalised to operators of fixed chargeQinO(N)theory and verified up to three loops in perturbation theory at leading and sub-leading order. Here we extend this verification to four loops inO(N)theory, once again at leading and sub-leading order. We also investigate the strong-coupling regime.

We study monopole operators with the lowest possible topological chargeq=1/2at the infrared fixed point of scalar electrodynamics in2+1dimension (scalar QED3) withNcomplex scalars and Chern-Simons coupling|k|=N. In the largeNexpansion, monopole operators in this theory with spins??O(N??????)and associated flavor representations are expected to have the same scaling dimension to sub-leading order in1/N. We use the state-operator correspondence to calculate the scaling dimension to sub-leading order with the resultN??.2743+O(1/N), which improves on existing leading order results. We also compute the??2/Nterm that breaks the degeneracy to sub-leading order for monopoles with spins??O(N??????).

The coupling between the spin of a massive Dirac fermion and the angular momentum of the medium, i.e. the gravitomagnetic moment, is shown here to be renormalized by QED interactions at finite temperature. This means that the anomalous gravitomagnetic moment (AGM) does not vanish, and implies that thermal effects can break the Einstein equivalence principle in quantum field theory, as argued previously. We also show that the AGM causes radiative corrections to the axial current of massive fermions induced by vorticity in quantum relativistic fluids, similarly to the previous findings for massless fermions. The radiative QCD effects on the AGM should significantly affect the production of polarized hadrons in heavy-ion collisions.

We present an analytic study of conformal field theories on the real projective spaceRPd, focusing on the two-point functions of scalar operators. Due to the partially broken conformal symmetry, these are non-trivial functions of a conformal cross ratio and are constrained to obey a crossing equation. After reviewing basic facts about the structure of correlators onRPd, we study a simple holographic setup which captures the essential features of boundary correlators onRPd. The analysis is based on calculations of Witten diagrams on the quotient spaceAdSd+1/Z2, and leads to an analytic approach to two-point functions. In particular, we argue that the structure of the conformal block decomposition of the exchange Witten diagrams suggests a natural basis of analytic functionals, whose action on the conformal blocks turns the crossing equation into certain sum rules. We test this approach in the canonical example ofϕ4theory in dimensiond=4−ϵ, extracting the CFT data to orderϵ2. We also check our results by standard field theory methods, both in the largeNandϵexpansions. Finally, we briefly discuss the relation of our analysis to the problem of construction of local bulk operators in AdS/CFT.

We discuss various aspects of anisotropic gravity in(d+D)-dimensional spacetime whereD-dimensions are treated as extra dimensions. It is based on a foliation preserving diffeomorphism(FPD) invariance and an anisotropic conformal invariance. The anisotropy is embodied by introducing a factorzwhich characterizes the scaling degree of the extraD-dimensions against thed-dimensional base spacetime. There is no intrinsic scale in our model but a physical scaleM??emerges as a consequence of spontaneous conformal symmetry breaking of Weyl scalar field which mediates the anisotropic scaling symmetry. Some vacuum solutions are obtained and we discuss an issue of `size separation' between the base spacetime and the extra dimensions. The size separation means large hierarchy between the scales appearing in the base spacetime and the extra dimensions respectively. We also discuss interesting theories obtained from our model. In a(d,D)=(2,2)case, we suggest a UV-complete quantum gravity which might become Einstein-Hilbert theory in IR. In the case of (4,1), we propose a resolution of hierarchy problem and discuss comparison with brane-world model's results. In a certain (2,1) case, we obtain CGHS-model.

Recently it was shown that classical electromagnetism admits new asymptotic conservation laws \cite{2007.03627}. In this paper we derive the analogue of the first of these asymptotic conservation laws upon imposing Feynman boundary condition on the radiative field. We also show that the Feynman solution atO(e3)contains purely imaginary modes falling off as{loguunr,n??}which are absent in the classical radiative solution. Thelogumode has also appeared in \cite{1903.09133,1912.10229} and violates the Ashtekar-Struebel fall offs for the radiative field\cite{AS}. We expect that new(logu)mumr-modes would appear in the Feynman solution at orderO(e2m+1). Thus, all the other modes are expected to preserve the Ashtekar-Struebel fall offs.