Searcharxiv⌕ Search

arXiv · 2610.10562

A Braak-Inspired Spectral Determinant Approach to a Dirac Bound-State Problem

Abstract

We develop a parity-resolved spectral-connection construction for a one-dimensional Dirac particle in an attractive soft-core Coulomb potential. The square-root dependence of the potential produces algebraic branch points in the coordinate plane. We uniformize these branch points by introducing \(t=\sqrt{x^2+β^2}\), while retaining the full-line \(Z_2\) symmetry generated by \(Π=σ_z P_x\). In each parity sector the resulting problem is formulated as a global connection problem between a solution selected at the physical origin and the decaying solution at infinity. This defines parity-resolved spectral connection functions whose zeros determine bound-state energies. We further construct a quasi-exact Bethe-ansatz sector directly from the same Dirac equations and use its polynomial solutions as independent benchmarks of the spectral condition. The comparison clarifies the distinction between local quasi-exact solvability and the global spectral determinant. The construction is inspired by the role of discrete symmetry and global analyticity in the quantum Rabi model, without identifying the present spectral function with Braak's \(G\)-function.

Explore related subjects

Keep this discovery

Explore connections, maps & timelines

BibTeXRIS

Saber Zarrinkamar. 2026-10-01. A Braak-Inspired Spectral Determinant Approach to a Dirac Bound-State Problem. https://arxiv.org/abs/2610.10562

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related papers

Finite Standard-Model Carrier from Timelike Codazzi Defects

The inverse problem of whether protected data carried by a local Lorentzian defect can determine a finite internal gauge-and-matter carrier before microscopic dynamics are chosen is considered. For a codimension-three timelike Codazzi defect, a marking-preserving reconstruction fixes a five-dimensional complex carrier $V=C\oplus W$ with $\dim_{\mathbb C}(C,W)=(3,2)$, the global gauge form $S(U(3)\times U(2))$, a chiral $16$-dimensional exterior packet with $k_Y=5/3$, and a norm-seven family structure. The chiral packet has the standard algebraic $SU(5)$-Spin$(10)$ envelope without assuming grand unification. Within a declared regularized-domain class, one constrained microscopic realization is constructed. Its distinguished branch ends at a single intrinsic terminal where the strict charge minimum and the first simple invariant-sector fixed-charge degeneracy coincide; soft-coupled readouts acquire a rank-one critical-response pole. On the rank-two exact-five moment stratum, four native matrix moments reconstruct a five-dimensional cyclic operator up to hidden unitary. The resulting scale-free observables lie on a one-dimensional solution manifold with a discrete conjugate orientation. With $W/Z$ used to set its longitudinal coordinate, direct CKM and reactor/solar data are consistent with the same manifold, while first-row CKM normalization remains a separate transverse structural test. Existence within the stated class is established, not uniqueness. A blind determination of the longitudinal coordinate still requires the unresolved centered-response incidence; physical transport remains an independent microscopic gate.

physics.gen-ph↗

Jacobi's principle of stationary full action and its implications

The purpose of this article is to extend the applicability of the principle of stationary Jacobi action to non-conservative natural systems and to derive the equations of motion corresponding to this generalized principle. To this end, in addition to the well-known variation of the Jacobi action with respect to coordinates, we introduce an independent variation of time. Small variations in both coordinates and time are considered at points along the actual trajectory, subject to standard boundary conditions.

physics.gen-ph↗

$\cal{PT}$-Symmetric GUP-Modified Single- and Double-Well Quartic Oscillators

We study the GUP-deformed quartic oscillator $H_η=p^2+ηp^4+x^4$ and distinguish its real-axis realization from complex-contour realizations. A contour chosen to remain in the decay sectors compatible with the undeformed quartic oscillator gives low-lying eigenvalues that approach the ordinary quartic spectrum as $η\to0^+$. This limiting-compatible contour does not, by itself, produce a low-level $\PT$-symmetry-breaking transition. To investigate exceptional points while retaining the same quartic leading behavior, we then introduce the explicitly $\PT$-symmetric extension $H_{η,a,g}=p^2+ηp^4+x^4-a x^2+\ii g x^3$ and fix $a=4$, for which the real part of the potential has a double-well form. Harmonic-oscillator-basis diagonalization with basis dimensions up to $N=100$ yields a converged exceptional-point branch: the critical coupling increases from $g_{\mathrm{EP}}\simeq0.10222364$ at $η=0$ to $g_{\mathrm{EP}}\simeq0.15603309$ at $η=0.1$. Across the transition, the two lowest real eigenvalues coalesce and continue as a complex-conjugate pair. The exceptional-point results belong to this stated double-well extension, not to the original single-well Hamiltonian alone.

physics.gen-ph↗