492 research outputs found
Price vs. quantity in oligopoly games
Price-setting and quantity-setting oligopoly games lead to
extremely dierent outcomes in the market. One natural way to address this problem is to formulate a model in which some rms use price while the remaining rms use quantity as their decision variable. We introduce a mixed oligopoly game of this type and determine its equilibria. In addition, we consider an extension of this mixed oligopoly game through which the choice of the decision variables can be endogenized. We prove the emergence of the Cournot game
An efficient and flexible approach for computing rovibrational polaritons from first principles
A theoretical framework is presented for the computation of rovibrational
polaritonic states of a molecule in a lossless infrared (IR) microcavity. In
the proposed approach the quantum treatment of the rotational and vibrational
motion of the molecule can be formulated using arbitrary approximations. The
cavity-induced changes in electronic structure are treated perturbatively,
which allows using the existing polished tools of standard quantum chemistry
for determining electronic molecular properties. As a case study, the
rovibrational polaritons and related thermodynamic properties of HO in an
IR microcavity are computed for varying cavity parameters and applying various
approximations to describe the molecular degrees of freedom. The self-dipole
interaction is found to be significant for nearly all light-matter coupling
strengths investigated, and the molecular polarizability proved to be important
for the correct qualitative behavior of the energy level shifts induced by the
cavity. On the other hand, the magnitude of polarization remains small,
justifying the perturbative approach for the cavity-induced changes in
electronic structure. Comparing results obtained using a high-accuracy
variational molecular model with those obtained utilizing the rigid rotor and
harmonic oscillator approximations revealed that as long as the rovibrational
model is appropriate for describing the field-free molecule, the computed
rovibropolaritonic properties can be expected to be accurate as well. Strong
light-matter coupling between the radiation mode of an IR cavity and the
rovibrational states of HO lead to minor changes in the thermodynamic
properties of the system, and these changes seem to be dominated by
non-resonant interactions between the quantum light and matter
Three-player polaritons: nonadiabatic fingerprints in an entangled atom-molecule-photon system
A quantum system composed of a molecule and an atomic ensemble, confined in a
microscopic cavity, is investigated theoretically. The indirect coupling
between atoms and the molecule, realized by their interaction with the cavity
radiation mode, leads to a coherent mixing of atomic and molecular states, and
at strong enough cavity field strengths hybrid atom-molecule-photon polaritons
are formed. It is shown for the Na molecule that by changing the cavity
wavelength and the atomic transition frequency, the potential energy landscape
of the polaritonic states and the corresponding spectrum could be changed
significantly. Moreover, an unforeseen intensity borrowing effect, which can be
seen as a strong nonadiabatic fingerprint, is identified in the atomic
transition peak, originating from the contamination of the atomic excited state
with excited molecular rovibronic states
Pauli principle in polaritonic chemistry
Consequences of enforcing permutational symmetry, as required by the Pauli
principle (spin-statistical theorem), on the state space of molecular ensembles
interacting with the quantized radiation mode of a cavity are discussed. The
Pauli-allowed collective states are obtained by means of group theory, i.e., by
projecting the state space onto the appropriate irreducible representations of
the permutation group of the indistinguishable molecules. It is shown that with
increasing number of molecules the ratio of Pauli-allowed collective states
decreases very rapidly. Bosonic states are more abundant than fermionic states,
and the brightness of Pauli-allowed collective states (contribution from photon
excited states) increases(decreases) with increasing fine structure in the
energy levels of the material ground(excited) state manifold. Numerical results
are shown for the realistic example of rovibrating HO molecules interacting
with an infrared (IR) cavity mode
Finite Neighborhood Binary Games: a Structural Study
The purpose of this study is to present a systematic analysis of the long-term behavior of the agents of an artificial society under varying payoff functions in finite neighborhood binary games. By assuming the linearity of the payoffs of both cooperating and defecting agents, the type of the game is determined by four fundamental parameters. By fixing the values of three of them and systematically varying the fourth one we can observe a transition from Prisoner\'s Dilemma to Leader Game through Chicken and Benevolent Chicken Games. By using agent-based simulation we are able to observe the long-term behavior of the artificial society with different and gradually changing payoff structure. The difference between different games is explored and the effect of the transition from one game to the other on the society is investigated. The results depend on the personality types of the agents. In this study greedy and Pavlovian agents are considered. In the first case, we observe the most significant change in trajectory structure between Prisoner\'s Dilemma and Chicken Games showing significant difference in the behavioral patterns of the agents. Almost no changes can be observed between Benevolent Chicken and Leader Games, and only small change between Chicken and Benevolent Chicken. The trajectories change from always converging to regularly oscillating patterns with systematically altering amplitude and central values. The results are very similar whether the agents consider themselves as members of their neighborhoods or not. With Pavlovian agents no significant difference can be observed between the four games, the trajectories always converge and the limits smoothly and monotonically depend on the value of the varying parameter.Agent-Based Simulation, N-Person Games, Structure Analysis, Equilibrium
Robust field-dressed spectra of diatomics in an optical lattice
The absorption spectra of the cold Na2 molecule dressed by a linearly
polarized standing laser wave is investigated. In the studied scenario the
rotational motion of the molecules is frozen while the vibrational and
translational degrees of freedom are accounted for as dynamical variables. In
such a situation a light-induced conical intersection (LICI) can be formed. To
measure the spectra a weak field is used whose propagation direction is
perpendicular to the direction of the dressing field but has identical
polarization direction. Although LICIs are present in our model, the
simulations demonstrate a very robust absorption spectrum, which is insensitive
to the intensity and the wavelength of the dressing field and which does not
reflect clear signatures of light-induced nonadiabatic phenomena related to the
strong mixing between the electronic, vibration and translational motions.
However, by widening artificially the very narrow translational energy level
gaps, the fingerprint of the LICI appears to some extent in the spectrum
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