Search arXivSearch

arXiv · 2606.05214

Analytic umbral transmutations and Bessel moments

Abstract

We develop an analytic umbral approach to Bessel moments, using them as a concrete testbed justifying the passage from formal indicial umbral calculus to Mellin--Barnes umbral transmutation theory. [...] While the formal procedure reproduces the correct results in suitable convergence chambers, it may lead to non-admissible hypergeometric expansions at physically relevant parameter values. The cubic moment provides the basic example [...] We show that this obstruction is removed by replacing the purely formal expansion with an analytic umbral transmutation. In this setting, exponential umbral pairings are interpreted through Mellin--Barnes integrals, and Ramanujan's Master Theorem acts as an inverse selection principle for the spectral ground state, or clock, associated with a given Bessel product. The factorisation \(J_0^3=J_0J_0^2\) produces two distinct clocks and reduces the cubic full-line moment to a one-dimensional Barnes integral, equivalently to a Meijer \(G\)-function. This gives the classical value of the cubic Bessel moment and clarifies why the divergent Appell realisation is only a local representation of a globally meaningful umbral identity. The same mechanism is then applied to scaled cubic products and to the fourth Bessel moment. [...] The fifth moment marks the first genuinely higher-rank case: the natural umbral grouping leads to a bivariate Barnes transmutation rather than to an ordinary Meijer \(G\)-function. Finally, we discuss real fractional powers \(J_0^α\), \(α>2\), showing that the same interpretation persists beyond integer moments. [...] The resulting picture identifies Bessel moments as values of effective umbral transmutations and separates the global analytic meaning of the umbral representation from the local convergence properties of its hypergeometric residue expansions.

Explore related subjects

Keep this discovery

Explore connections, maps & timelines

BibTeXRIS

Roberto Ricci, Giuseppe Dattoli. 2026-05-27. Analytic umbral transmutations and Bessel moments. https://arxiv.org/abs/2606.05214

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

KEEP EXPLORING

Related papers

On Hilbert's 8th Problem

This note takes the probabilistic half of the Riemann Xi story on its own terms. Every object in the subject is a first passage time: Riemann's kernel is the law of the logarithm of a sum of two hitting times of a three dimensional Bessel process, Polya's approximation is the first passage of a Brownian motion with drift, and the reciprocal Xi function, under the Riemann hypothesis, is the Laplace transform of an infinite convolution of exponentials whose rates are the squared zeros. That reciprocal is written as $F_α(s)=ξ(α)/ξ(α+\sqrt s)$, and complete monotonicity, unconditional for $α\ge1$, is conjectured to persist to the critical basepoint $α=1/2$. Kent's eigenvalue expansion says which laws can arise this way, namely those whose Thorin measure is a Dirichlet spectrum with unit atoms, and Krein's inverse spectral theory turns the hypothesis into the existence of a string. The passage from Riemann to Polya is a flow, not a jump: the Cauchy semigroup on Thorin measures, each step an Esscher tilt followed by a Brownian subordination along a curvature family of hyperbolic Bessel processes, with the arithmetic surviving as Fourier modes damped like $e^{-2πk\varepsilon}$. The arithmetic lives in the atoms and nowhere else. Approximations rank by what they keep: Polya keeps neither atoms nor tempering and is off by a factor of three, a fitted Bessel dimension reaches one per cent, and a few atoms with an erfc tempering stay better than one part in a thousand across four decades. And the flow runs backwards: the Thorin measure of the reciprocal is evaluated from a prime sieve with no reference to any zero, and nonnegative deconvolution of it returns the first ten zero ordinates with unit masses, nine of them to four decimals and one to three. All identities are verified with mpmath, and the scripts are included.

math.GM

Dynamical Geometry of Principal Bundle Constrained Systems: Compatible Pairs, Contact Degeneration, and Adapted Metrics

We study invariant codimension-one constraints on principal bundles through compatible pairs: a constraint distribution and a nonzero coadjoint field parallel for a principal connection. Pairing the field with the connection gives an invariant one-form whose Levi form separates a horizontal curvature contribution from a vertical coadjoint-orbit contribution. This decomposition yields criteria for integrability, contactness, and characteristic reduction; holonomy and stabilizer reductions describe global existence. For evolving compatible pairs, we identify the mixed-curvature obstruction to compatibility and prove that connection transport preserves the Levi geometry. For initially contact data over a closed base of dimension $2n$, we establish matching bounds for the quadratic $H^{n+1}$ cost of contact degeneration: making the paired curvature vanish on a Darboux ball of radius $r$ in time $T$ costs an amount comparable to $[T\log(R_*/r)]^{-1}$. The constructed paths remain contact before $T$, preserve the curvature class, and force the $L^\infty$ norm of every transporting velocity gradient to grow at least as $1/[2(T-t)]$ on the collapsing region in Darboux coordinates. On a closed three-manifold, a contact form preserved by a locally free circle action admits an invariant adapted metric with any prescribed positive curl eigenvalue and unit circle generator. We parametrize all such metrics and prove that their space is contractible. Along the circle-bundle degeneration paths, every continuous tensor limit of normalized adapted metrics is degenerate above the collapsing region.

math.GM