1,024 research outputs found
Cylindrical Wiener processes
In this work cylindrical Wiener processes on Banach spaces are defined by
means of cylindrical stochastic processes, which are a well considered
mathematical object. This approach allows a definition which is a simple
straightforward extension of the real-valued situation. We apply this
definition to introduce a stochastic integral with respect to cylindrical
Wiener processes. Again, this definition is a straightforward extension of the
real-valued situation which results now in simple conditions on the integrand.
In particular, we do not have to put any geometric constraints on the Banach
space under consideration. Finally, we relate this integral to well-known
stochastic integrals in literature
Heterogeneous perturbations in the Doppler-free S1 ← S0 two-photon spectrum of benzene: Evidence for intrastate coupling
Rotational perturbations are identified in Doppler-free two-photon spectra of the 1410 and 1410110 vibronic bands in C6H6. Evidence is found that Coriolis coupling between some of the rotational levels of two distinct vibrational states within S1 is the mechanism responsible. This coupling mechanism is thought to be responsible for irreversible intramolecular relaxation at higher excess energies and higher vibrational state densities
Ornstein-Uhlenbeck processes driven by cylindrical L\'evy processes
In this article we introduce a theory of integration for deterministic,
operator-valued integrands with respect to cylindrical L\'evy processes in
separable Banach spaces. Here, a cylindrical L\'evy process is understood in
the classical framework of cylindrical random variables and cylindrical
measures, and thus, it can be considered as a natural generalisation of
cylindrical Wiener processes or white noises. Depending on the underlying
Banach space, we provide necessary and/or sufficient conditions for a function
to be integrable. In the last part, the developed theory is applied to define
Ornstein-Uhlenbeck processes driven by cylindrical L\'evy processes and several
examples are considered.Comment: This version is significantly revised and correcte
Sub-doppler two-photon spectrum of asymmetric rotor molecules
The Doppler-free two-photon excitation spectrum of the qqQ branch of the 1410 vibrational band of the S1(1B2u) ← S0(1A1g) transition of benzene-d1 has been recorded using a cw single-mode dye laser coupled to an external concentric resonator. The spectrum has been analysed using a non-rigid Watson Hamiltonian. More than 200 lines with J up to 20 have been assigned and the rotational constants which best reproduce the spectrum are A1v = 0.181435, B1v = 0.169990, C1v = 0.089055 cm−1. The Ka = odd lines of the qqQ5(J) subbranch show small and quite regular perturbations of 60 ± 5 MHz which are probably due to a coupling to another vibrational state of the S1 manifold
Infinitely divisible cylindrical measures on Banach spaces
In this work infinitely divisible cylindrical probability measures on
arbitrary Banach spaces are introduced. The class of infinitely divisible
cylindrical probability measures is described in terms of their
characteristics, a characterisation which is not known in general for
infinitely divisible Radon measures on Banach spaces. Further properties of
infinitely divisible cylindrical measures such as continuity are derived.
Moreover, the result on the classification enables us to conclude new results
on genuine Levy measures on Banach spaces
Mixing of the vibrational angular momentum components of multiply degenerate vibronic states of benzene by vibrational l-type resonance
The rotationally resolved spectra of the 6011002 and 6011602 vibronic transitions of benzene at low rotational temperat reported and analyzed in detail. Deperturbed spectroscopic constants for the 61102 and 61162 states are reported which reproduce the observed line positions to within experimental accuracy. The splitting of 17.9 cm−1 between the two subbands of the 6011002 transition and of 6.2 cm−1 for the 6011602 transition is found to be due to vibrational l-type resonances with matrix element 8.91 and 2.65 cm−1, respectively. These large resonances cause strong distortions of the rotational structure and mix the vibrational angular momentum substates ν6minus-or-plus sign + 2ν100 and ν6± + 2ν10±2 nearly completely and the substates ν6minus-or-plus sign + 2ν160 and ν6± + 2ν16minus-or-plus sign2 substantially. The importance of the mixing for the intramolecular vibrational redistribution (IVR) and the decay behaviour of S1 benzene is discussed
Radonifying operators and infinitely divisible Wiener integrals
In this article we illustrate the relation between the existence of Wiener
integrals with respect to a Levy process in a separable Banach space and
radonifying operators. For this purpose, we introduce the class of
theta-radonifying operators, i.e. operators which map a cylindrical measure
theta to a genuine Radon measure. We study this class of operators for various
examples of infinitely divisible cylindrical measures theta and highlight the
differences from the Gaussian case.Comment: 16 page
Invariant measure for the stochastic Cauchy problem driven by a cylindrical L\'evy process
In this work, we present sufficient conditions for the existence of a
stationary solution of an abstract stochastic Cauchy problem driven by an
arbitrary cylindrical L\'evy process, and show that these conditions are also
necessary if the semigroup is stable, in which case the invariant measure is
unique. For typical situations such as the heat equation, we significantly
simplify these conditions without assuming any further restrictions on the
driving cylindrical L\'evy process and demonstrate their application in some
examples
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