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Marco Matone

Publications and source records attributed to Marco Matone.

At least 19 recordsLinked to original sources

Quantum Mechanics from General Relativity and the Quantum Friedmann Equation

We demonstrate that the recently introduced linear equation, reformulating the first Friedmann equation, is the first-order WKB expansion of a quantum cosmological equation. This result shows a deeper underlying connection between General Relativity and Quantum Mechanics, pointing towards a unified framework. Solutions of this equation are built in terms of a scale factor encapsulating quantum effects on a free-falling particle. The quantum scale factor reshapes cosmic dynamics, resolving singularities at its vanishing points in several cases of interest. As an explicit example, we consider the radiation-dominated era and show that the quantum equation is dual to the one in Seiberg-Witten formulation, recently applied to black holes, and incorporates resurgence phenomena and complex metrics, as developed by Kontsevich, Segal, and Witten. This links to the invariance of time parametrization under $\Gamma(2)$ transformations of the dual wave function.

hep-th

Singular Spin Structures and Superstrings

There are two main problems in finding the higher genus superstring measure. The first one is that for $g\geq 5$ the super moduli space is not projected. Furthermore, the supermeasure is regular for $g\leq 11$, a bound related to the source of singularities due to the divisor in the moduli space of Riemann surfaces with even spin structure having holomorphic sections, such a divisor is called the $\theta$-null divisor. A result of this paper is the characterization of such a divisor. This is done by first extending the Dirac propagator, that is the Szeg\"o kernel, to the case of an arbitrary number of zero modes, that leads to a modification of the Fay trisecant identity, where the determinant of the Dirac propagators is replaced by the product of two determinants of the Dirac zero modes. By taking suitable limits of points on the Riemann surface, this {\it holomorphic Fay trisecant identity} leads to identities that include points dependent rank 3 quadrics in $\mathbb{P}^{g-1}$. Furthermore, integrating over the homological cycles gives relations for the Riemann period matrix which are satisfied in the presence of Dirac zero modes. Such identities characterize the $\theta$-null divisor. Finally, we provide the geometrical interpretation of the above points dependent quadrics and shows, via a new $\theta$-identity, its relation with the Andreotti-Mayer quadric.

hep-th

Universe as Klein-Gordon Eigenstates

We formulate Friedmann's equations as second-order linear differential equations. This is done using techniques related to the Schwarzian derivative that selects the $\beta$-times $t_\beta:=\int^t a^{-2\beta}$, where $a$ is the scale factor. In particular, it turns out that Friedmann's equations are equivalent to the eigenvalue problems $$ O_{1/2} \Psi=\frac{\Lambda}{12}\Psi \ , \qquad O_1 a =\frac{\Lambda}{3} a \ , $$ which is suggestive of a measurement problem. $O_{\beta}(\rho,p)$ are space-independent Klein-Gordon operators, depending only on energy density and pressure, and related to the Klein-Gordon Hamilton-Jacobi equations. The $O_\beta$'s are also independent of the spatial curvature, labeled by $k$, and absorbed in $$ \Psi=\sqrt a e^{\frac{i}{2}\sqrt{k}\eta} \ . $$ The above pair of equations is the unique possible linear form of Friedmann's equations unless $k=0$, in which case there are infinitely many pairs of linear equations. Such a uniqueness just selects the conformal time $\eta\equiv t_{1/2}$ among the $t_\beta$'s, which is the key to absorb the curvature term. An immediate consequence of the linear form is that it reveals a new symmetry of Friedmann's equations in flat space.

hep-th

The Geometrical Origin of Dark Energy

The geometrical formulation of the quantum Hamilton-Jacobi theory shows that the quantum potential is never trivial, so that it plays the r\^ole of intrinsic energy. Such a key property selects the Wheeler-DeWitt (WDW) quantum potential $Q[g_{jk}]$ as the natural candidate for the dark energy. This leads to the WDW Hamilton-Jacobi equation with a vanishing kinetic term, and with the identification $$ \Lambda=-\frac{\kappa^2}{\sqrt{\bar g}}Q[g_{jk}] \ . $$ This shows that the cosmological constant is a quantum correction of the Einstein tensor, reminiscent of the von Weizs\"acker correction to the kinetic term of the Thomas-Fermi theory. The quantum potential also defines the Madelung pressure tensor. The geometrical origin of the vacuum energy density, a strictly non-perturbative phenomenon, provides strong evidence that it is due to a graviton condensate. Time independence of the regularized WDW equation suggests that the ratio between the Planck length and the Hubble radius may be a time constant, providing an infrared/ultraviolet duality. We speculate that such a duality is related to the local to global geometry theorems for constant curvatures, showing that understanding the universe geometry is crucial for a formulation of Quantum Gravity.

hep-th

On the Baker-Campbell-Hausdorff Theorem: non-convergence and prolongation issues

We investigate some topics related to the celebrated Baker-Campbell-Hausdorff Theorem: a non-convergence result and prolongation issues. Given a Banach algebra $\mathcal{A}$ with identity $I$, and given $X,Y\in \mathcal{A}$, we study the relationship of different issues: the convergence of the BCH series $\sum_n Z_n(X,Y)$, the existence of a logarithm of $e^Xe^Y$, and the convergence of the Mercator-type series $\sum_n {(-1)^{n+1}}(e^Xe^Y-I)^n/n$ which provides a selected logarithm of $e^Xe^Y$. We fix general results and, by suitable matrix counterexamples, we show that various pathologies can occur, among which we provide a non-convergence result for the BCH series. This problem is related to some recent results, of interest in physics, on closed formulas for the BCH series: while the sum of the BCH series presents several non-convergence issues, these closed formulas can provide a prolongation for the BCH series when it is not convergent. On the other hand, we show by suitable counterexamples that an analytic prolongation of the BCH series can be singular even if the BCH series itself is convergent.

math-ph

Quantum Mechanics from Ergodic Average of Microstates

We formulate quantum mechanics as an effective theory of an underlying structure characterized by microstates $|{\mathcal M}^j(t)\rangle$, each one defined by the quantum state $|\Psi(t)\rangle$ and a complete set of commutative observables $O^j$. At any time $t$, $|{\mathcal M}^j(t)\rangle$ corresponds to a state $|O^j_k\rangle$, for some $k$ depending on $t$, and jumps after time intervals whose duration, of the order of the Compton time $\tau$, is proportional to the probability $|\langle O_k^j|\Psi(t)\rangle|^2$. This reproduces the Born rule and mimics the wave-particle duality. The theory is based on a partition of time whose flow is characterized by quantum probabilities. Ergodicity arises at ordinary quantum scales with the expectation values corresponding to time averaging over a period $\tau$. The measurement of $O^j$ provides a new partition of time and the outcome is the state $|O_k^j\rangle$ to which $|{\mathcal M}^j(t)\rangle$ corresponds at that time. The formulation, that shares some features with the path integral, can be tested by experiments involving time intervals of order $\tau$.

quant-ph

Dual representation for the generating functional of the Feynman path-integral

The generating functional for scalar theories admits a representation which is dual with respect to the one introduced by Schwinger, interchanging the role of the free and interacting terms. It maps $\int V(\delta_J)$ and $J\Delta J$ to $\delta_{\phi_c}\Delta\delta_{\phi_c}$ and $\int V(\phi_c)$, respectively, with $\phi_c=\int J\Delta$ and $\Delta$ the Feynman propagator. Comparing the Schwinger representation with its dual version one gets a little known relation that we prove to be a particular case of a more general operatorial relation. We then derive a new representation of the generating functional $T[\phi_c]=W[J]$ expressed in terms of covariant derivatives acting on 1 $$ T[\phi_c] = {N\over N_0} \exp(-U_0[\phi_c])\exp\Big(-\int V({\cal D}_{\phi_c}^-)\Big) \cdot 1 $$ where ${\cal D}_{\phi}^{\pm}(x)=\mp\Delta{\delta\over\delta\phi}(x)+\phi(x)$. The dual representation, which is deeply related to the Hermite polynomials, is the key to express the generating functional associated to a sum of potentials in terms of factorized generating functionals. This is applied to renormalization, leading to a factorization of the counterterms of the interaction. We investigate the structure of the functional generator for normal ordered potentials and derive an infinite set of relations in the case of the potential ${\lambda\over n!}:\phi^n:$. Such relations are explicitly derived by using the Fa\`a di Bruno formula. This also yields the explicit expression of the generating functional of connected Green's functions.

hep-th

Exponentiating Higgs

We consider two related formulations for mass generation in the $U(1)$ Higgs-Kibble model and in the Standard Model (SM). In the first model there are no scalar self-interactions and, in the case of the SM, the formulation is related to the normal subgroup of $G=SU(3)\times SU(2)\times U(1)$, generated by $(e^{2\pi i/3}I,-I,e^{\pi i/3})\in G$, that acts trivially on all the fields of the SM. The key step of our construction is to relax the non-negative definiteness condition for the Higgs field due to the polar decomposition. This solves several stringent problems, that we will shortly review, both in the perturbative and non-perturbative formulations. We will show that the usual polar decomposition of the complex scalar doublet $\Phi$ should be done with $U\in SU(2)/Z_2\simeq SO(3)$, where $Z_2$ is the group generated by $-I$, and with the Higgs field $\phi\in R$ rather than $\phi\in R_{\geq0}$. As a byproduct, the investigation shows how Elitzur theorem may be avoided in the usual formulation of the SM. It follows that the simplest lagrangian density for the Higgs mechanism has the standard kinetic term in addition to the mass term, with the right sign, and to a linear term in $\phi$. The other model concerns the scalar theories with normal ordered exponential interactions. The remarkable property of these theories is that for $D>2$ the purely scalar sector corresponds to a free theory.

hep-th

Quantum Field Perturbation Theory Revisited

Schwinger's formalism in quantum field theory can be easily implemented in the case of scalar theories in $D$ dimension with exponential interactions, such as $\mu^D\exp(\alpha\phi)$. In particular, we use the relation $$ \exp\big(\alpha{\delta\over \delta J(x)}\big)\exp(-Z_0[J])=\exp(-Z_0[J+\alpha_x]) $$ with $J$ the external source, and $\alpha_x(y)=\alpha\delta(y-x)$. Such a shift is strictly related to the normal ordering of $\exp(\alpha\phi)$ and to a scaling relation which follows by renormalizing $\mu$. Next, we derive a new formulation of perturbation theory for the potentials $V(\phi)={\lambda\over n!}:\phi^n:$, using the generating functional associated to $:\exp(\alpha\phi):$. The $\Delta(0)$-terms related to the normal ordering are absorbed at once. The functional derivatives with respect to $J$ to compute the generating functional are replaced by ordinary derivatives with respect to auxiliary parameters. We focus on scalar theories, but the method is general and similar investigations extend to other theories.

hep-th

Wilson Loops on Riemann Surfaces, Liouville Theory and Covariantization of the Conformal Group

The covariantization procedure is usually referred to the translation operator, that is the derivative. Here we introduce a general method to covariantize arbitrary differential operators, such as the ones defining the fundamental group of a given manifold. We focus on the differential operators representing the sl(2,R) generators, which in turn, generate, by exponentiation, the two-dimensional conformal transformations. A key point of our construction is the recent result on the closed forms of the Baker-Campbell-Hausdorff formula. In particular, our covariantization receipt is quite general. This has a deep consequence since it means that the covariantization of the conformal group is {\it always definite}. Our covariantization receipt is quite general and apply in general situations, including AdS/CFT. Here we focus on the projective unitary representations of the fundamental group of a Riemann surface, which may include elliptic points and punctures, introduced in the framework of noncommutative Riemann surfaces. It turns out that the covariantized conformal operators are built in terms of Wilson loops around Poincar\'e geodesics, implying a deep relationship between gauge theories on Riemann surfaces and Liouville theory.

hep-th

Closed Form of the Baker-Campbell-Hausdorff Formula for the Generators of Semisimple Complex Lie Algebras

Recently it has been introduced an algorithm Baker-Campbell-Hausdorff (BCH) formula, which extends the Van-Brunt and Visser recent results, leading to new closed forms of BCH formula. More recently, it has been shown that there are {\it 13 types} of such commutator algebras. We show, by providing the explicit solutions, that these include the generators of the semisimple complex Lie algebras. More precisely, for any pair, $X$, $Y$ of the Cartan-Weyl basis, we find $W$, linear combination of $X$, $Y$, such that $$ \exp(X) \exp(Y)=\exp(W) $$ The derivation of such closed forms follows, in part, by using the above mentioned recent results. The complete derivation is provided by considering the structure of of the root system. Furthermore, if $X$, $Y$ and $Z$ are three generators of the Cartan-Weyl basis, we find, for a wide class of cases, $W$, linear combination of $X$, $Y$ and $Z$, such that $$ \exp(X) \exp(Y) \exp(Z)=\exp(W) $$ It turns out that the relevant commutator algebras are {\it type 1c-i}, {\it type 4} and {\it type 5}. A key result concerns an iterative application of the algorithm leading to relevant extensions of the cases admitting closed forms of the BCH formula. Here we provide the main steps of such an iteration that will be developed in a forthcoming paper.

math-ph

A Surprising Relation for the Effective Coupling Constants of N=2 Super Yang-Mills Theories

We show that the effective coupling constants $\tau$ of supersymmetric gauge theories described by hyperelliptic curves do not distinguish between the lattices of the two kinds of heterotic string. In particular, the following relation $$ \Theta_{D_{16}^+}(\tau)=\Theta_{E_8}^2(\tau) $$ holds. This is reminiscent of the relation, by $T$-duality, of the two heterotic strings. We suggest that such a relation extends to all curves describing effective supersymmetric gauge theories.

hep-th

Classification of Commutator Algebras Leading to the New Type of Closed Baker-Campbell-Hausdorff Formulas

We show that there are {\it 13 types} of commutator algebras leading to the new closed forms of the Baker-Campbell-Hausdorff (BCH) formula $$\exp(X)\exp(Y)\exp(Z)=\exp({AX+BZ+CY+DI}) \ , $$ derived in arXiv:1502.06589, JHEP {\bf 1505} (2015) 113. This includes, as a particular case, $\exp(X) \exp(Z)$, with $[X,Z]$ containing other elements in addition to $X$ and $Z$. The algorithm exploits the associativity of the BCH formula and is based on the decomposition $\exp(X)\exp(Y)\exp(Z)=\exp(X)\exp({\alpha Y}) \exp({(1-\alpha) Y}) \exp(Z)$, with $\alpha$ fixed in such a way that it reduces to $\exp({\tilde X})\exp({\tilde Y})$, with $\tilde X$ and $\tilde Y$ satisfying the Van-Brunt and Visser condition $[\tilde X,\tilde Y]=\tilde u\tilde X+\tilde v\tilde Y+\tilde cI$. It turns out that $e^\alpha$ satisfies, in the generic case, an algebraic equation whose exponents depend on the parameters defining the commutator algebra. In nine {\it types} of commutator algebras, such an equation leads to rational solutions for $\alpha$. We find all the equations that characterize the solution of the above decomposition problem by combining it with the Jacobi identity.

math-ph

Hamilton--Jacobi meet M\"obius

Adaptation of the Hamilton--Jacobi formalism to quantum mechanics leads to a cocycle condition, which is invariant under $D$--dimensional M\"obius transformations with Euclidean or Minkowski metrics. In this paper we aim to provide a pedagogical presentation of the proof of the M\"obius symmetry underlying the cocycle condition. The M\"obius symmetry implies energy quantization and undefinability of quantum trajectories, without assigning any prior interpretation to the wave function. As such, the Hamilton--Jacobi formalism, augmented with the global M\"obius symmetry, provides an alternative starting point, to the axiomatic probability interpretation of the wave function, for the formulation of quantum mechanics and the quantum spacetime. The M\"obius symmetry can only be implemented consistently if spatial space is compact, and correspondingly if there exist a finite ultraviolet length scale. Evidence for non--trivial space topology may exist in the cosmic microwave background radiation.

hep-th

An algorithm for the Baker-Campbell-Hausdorff formula

A simple algorithm, which exploits the associativity of the BCH formula, and that can be generalized by iteration, extends the remarkable simplification of the Baker-Campbell-Hausdorff (BCH) formula, recently derived by Van-Brunt and Visser. We show that if $[X,Y]=uX+vY+cI$, $[Y,Z]=wY+zZ+dI$, and, consistently with the Jacobi identity, $[X,Z]=mX+nY+pZ+eI$, then $$ \exp(X)\exp(Y)\exp(Z)=\exp({aX+bY+cZ+dI}) $$ where $a$, $b$, $c$ and $d$ are solutions of four equations. In particular, the Van-Brunt and Visser formula $$\exp(X)\exp(Z)=\exp({aX+bZ+c[X,Z]+dI}) $$ extends to cases when $[X,Z]$ contains also elements different from $X$ and $Z$. Such a closed form of the BCH formula may have interesting applications both in mathematics and physics. As an application, we provide the closed form of the BCH formula in the case of the exponentiation of the Virasoro algebra, with ${\rm SL}_2({\rm C})$ following as a subcase. We also determine three-dimensional subalgebras of the Virasoro algebra satisfying the Van-Brunt and Visser condition. It turns out that the exponential form of ${\rm SL}_2({\rm C})$ has a nice representation in terms of its eigenvalues and of the fixed points of the corresponding M\"obius transformation. This may have applications in Uniformization theory and Conformal Field Theories.

math-ph

The M\"obius Symmetry of Quantum Mechanics

The equivalence postulate approach to quantum mechanics aims to formulate quantum mechanics from a fundamental geometrical principle. Underlying the formulation there exists a basic cocycle condition which is invariant under $D$--dimensional M\"obius transformations with respect to the Euclidean or Minkowski metrics. The invariance under global M\"obius transformations implies that spatial space is compact. Furthermore, it implies energy quantisation and undefinability of quantum trajectories without assuming any prior interpretation of the wave function. The approach may be viewed as conventional quantum mechanics with the caveat that spatial space is compact, as dictated by the M\"obius symmetry, with the classical limit corresponding to the decompactification limit. Correspondingly, there exists a finite length scale in the formalism and consequently an intrinsic regularisation scheme. Evidence for the compactness of space may exist in the cosmic microwave background radiation.

hep-th

Energy Quantisation and Time Parameterisation

We show that if space is compact, then trajectories cannot be defined in the framework of quantum Hamilton--Jacobi equation. The starting point is the simple observation that when the energy is quantized it is not possible to make variations with respect to the energy, and the time parameterisation t-t_0=\partial_E S_0, implied by Jacobi's theorem and that leads to group velocity, is ill defined. It should be stressed that this follows directly form the quantum HJ equation without any axiomatic assumption concerning the standard formulation of quantum mechanics. This provides a stringent connection between the quantum HJ equation and the Copenhagen interpretation. Together with tunneling and the energy quantization theorem for confining potentials, formulated in the framework of quantum HJ equation, it leads to the main features of the axioms of quantum mechanics from a unique geometrical principle. Similarly to the case of the classical HJ equation, this fixes its quantum analog by requiring that there exist point transformations, rather than canonical ones, leading to the trivial hamiltonian. This is equivalent to a basic cocycle condition on the states. Such a cocycle condition can be implemented on compact spaces, so that continuous energy spectra are allowed only as a limiting case. Remarkably, a compact space would also imply that the Dirac and von Neumann formulations of quantum mechanics essentially coincide. We suggest that there is a definition of time parameterisation leading to trajectories in the context of the quantum HJ equation having the probabilistic interpretation of the Copenhagen School.

hep-th

Finite Strings From Non-Chiral Mumford Forms

We show that there is an infinite class of partition functions with world-sheet metric, space-time coordinates and first order systems, that correspond to volume forms on the moduli space of Riemann surfaces and are free of singularities at the Deligne-Mumford boundary. An example is the partition function with 4=2(c_2+c_3+c_4-c_5) space-time coordinates, a $b$-$c$ system of weight 3, one of weight 4 and a beta-gamma system of weight 5. Such partition functions are derived from the mapping of the Mumford forms to non-factorized scalar forms on M_g introduced in arXiv:1209.6049.

hep-th