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Naoya Miyazaki

Publications and source records attributed to Naoya Miyazaki.

At least 19 recordsLinked to original sources

Augmented Star Products and their Applications

In this paper, we introduce a generalized framework for star products that preserve associativity while not necessarily obeying the canonical commutation relations. Within this framework, we formulate the augmented star product and investigate the associated augmented star exponentials. We further demonstrate several applications of these constructions to special functions and to problems arising in quantum physics.

math-ph

Oscillatory integrals with phase functions of positive real powers and asymptotic expansions

As to methods for expanding an oscillatory integral into an asymptotic series with respect to the parameter, the method of stationary phase for the non-degenerate phases and the method of using resolution of singularities for degenerate phases are known. The aim of this paper is to extend the former for degenerate phases with positive real powers without using resolution of singularities. For this aim, we first generalize Fresnel integrals as oscillatory integrals with phase functions of positive real powers. Next, by using this result, we have asymptotic expansions of oscillatory integrals for degenerate phases with positive real powers including moderate oscillations and for a wider amplitude class in one variable. Moreover, we obtain asymptotic expansions of oscillatory integrals for degenerate phases consisting of sums of monomials in each variable including the types $A_{k}$, $E_6$, $E_8$ in multivariable.

math.CA

Generalized Fresnel integrals as oscillatory integrals with positive real power phase functions and applications to asymptotic expansions

In this paper, we first generalize the Fresnel integrals by changing of a path for integration in the proof of the Fresnel integrals by Cauchy's integral theorem. Next, according to oscillatory integral, we also obtain further generalization of the extended Fresnel integrals. Moreover by using this result, we have an asymptotic expansion of an oscillatory integral with a positive real parameter, for a phase function with a degenerate critical point expressed by positive real power, including a moderate oscillation, and for a suitable amplitude function. This result gives a finer extension of the stationary phase method in one variable, which is known as a method for an asymptotic expansion of an oscillatory integral of a phase function with a non-degenerate critical point.

math.CA

On oscillatory integrals associated to phase functions with degenerate singular points

In this note, by using the result in one variable, we obtain asymptotic expansions of oscillatory integrals for certain multivariable phase functions with {\bf degenerate} singular points. Moreover by using this result, we have asymptotic expansions of oscillatory integrals with phase function of type $A_{k}$, $E_6$, $E_8$-function germs.

math.CA

Automorphisms of the Weyl manifold

Assume that $M$ is a smooth manifold with a symplectic structure $ω$. Then Weyl manifolds on the symplectic manifold $M$ are Weyl algebra bundles endowed with suitable transition functions. From the geometrical point of view, Weyl manifolds can be regarded as geometrizations of star products attached to $(M,ω)$. In the present paper, we are concerned with the automorphisms of the Weyl manifold corresponding to Poincaré-Cartan class ($c_0$ is a $\check{\rm C}$ech cocycle corresponding to the symplectic structure $ω$.) $[c_0+\sum_{\ell=1}^\infty c_{\ell} ν^{2\ell}]\in \check{H}^2 (M)[[ν^2]]$. We also construct modified contact Weyl diffeomorphisms.

math.DG

Quantization of Holomorphic Poisson structure --related to Generalized Kähler structure--

It is known that holomorphic Poisson structures are closely related to theories of generalized Kähler geometry and bi-Hermitian structures. In this article, we introduce quantization of holomorphic Poisson structures which are closely related to generalized Kähler structures /bi-Hermitian structures. By resulting noncommutative product $\star$ obtained via quantization, we also demonstrate computations with respect to concrete examples.

math.DG

Symbol calculus on a projective space

In this article, we introduce symbol calculus on a projective scheme. Using holomorphic Poisson structures, we construct deformations of ring structures for structure sheaves on projective spaces.

math.DG

Deformation Expression for Elements of Algebras (VII) --Vacuum/Pseudo-vacuum Representations--

Thinking back the long history of physics, we see that the calculation used by physicists was nothing but the ordinary calculus. Another word, physicists have never wrote theories beyond the basic axioms of the calculus. This is not to declare of the victory of calculus or algebraic topology. On the contrary, we are thinking that every theory of mathematical physics must suggest new frontier of ordinary calculus, which are never viewed by classical geometers. Weyl algebras or Heisenberg algebras are naturally involved in slightly extended systems of the algebra of ordinary calculus, and are supported by the classical notion of phase spaces on which the general mechanics are based. The theory of deformation quantizations gives a notion of quantization of "phase space". To explain its essence in brief we proposed in the previous note the notion of $μ$-regulated algebra. In this series, we have introduced elements, called "vacuums" to consider the state vectors and the configuration spaces within the world of extended algebra of calculus with various expressions. We have found several strange elements, called polar elements, and an extended notions of vacuums, which were called pseudo-vacuums in our paper. These are not established notions in mathematical physics, but we are thinking that these must propose new frontier for mathematical physics. We are thinking that vacuums and pseudo-vacuums are not unique, but the function algebra of the configuration spaces must be an algebra similar to the Frobenius algebra defined by vacuums. The point in this note is that to obtain classical pictures one has often to restrict the expression parameters, and there are two essentially different expression parameters.

math-ph

Deformation Expression for Elements of Algebras (II) --(Weyl algebra of 2m-generators)--

This is a noncommutative version of the previous work entitled "Deformation Expression for Elements of Algebras (I)." In general in a noncommutative algebra, there is no canonical way to express elements in univalent way, which is often called "ordering problem". In this note we discuss this problem in the case of the Weyl algebra of 2m-generators. By fixing an expression, we extends Weyl algebra transcendentally. We treat *-exponential functions of linear forms, and quadratic forms of crossed symbol under generic expression parameters.

math-ph

Deformation Expression for Elements of Algebras (IV) --Matrix elements and related integrals--

In this note, we mainly consider the extended Weyl algebra of two generators (u,v), that is, the algebra generated by u,v with the fundamental commutation relation. Weyl algebra is realized on the space of polynomials of u and v by defining various product depending on a symmetric matrix K called the expression parameter. Via such expressions and ordinary calculus one can treat various transcendental elements such as *-exponential functions and elements obtained by integrations.

math-ph

Geometric objects in an approach to quantum geometry

Ideas from deformation quantization applied to algebras with one generator lead to methods to treat a nonlinear flat connection. It provides us elements of algebras to be parallel sections. The moduli space of the parallel sections is studied as an example of bundle-like objects with discordant (sogo) transition functions, which suggests us to treat movable branching singularities.

math.QA