Search results for " Lower"
showing 10 items of 378 documents
Motzkin subposets and Motzkin geodesics in Tamari lattices
2014
The Tamari lattice of order n can be defined by the set D n of Dyck words endowed with the partial order relation induced by the well-known rotation transformation. In this paper, we study this rotation on the restricted set of Motzkin words. An upper semimodular join semilattice is obtained and a shortest path metric can be defined. We compute the corresponding distance between two Motzkin words in this structure. This distance can also be interpreted as the length of a geodesic between these Motzkin words in a Tamari lattice. So, a new upper bound is obtained for the classical rotation distance between two Motzkin words in a Tamari lattice. For some specific pairs of Motzkin words, this b…
A PHENOMENOLOGICAL OPERATOR DESCRIPTION OF INTERACTIONS BETWEEN POPULATIONS WITH APPLICATIONS TO MIGRATION
2013
We adopt an operatorial method based on the so-called creation, annihilation and number operators in the description of different systems in which two populations interact and move in a two-dimensional region. In particular, we discuss diffusion processes modeled by a quadratic hamiltonian. This general procedure will be adopted, in particular, in the description of migration phenomena. With respect to our previous analogous results, we use here fermionic operators since they automatically implement an upper bound for the population densities.
Advances in the enumeration of foldable self-avoiding walks
2020
<font color="#336633">Self-avoiding walks (SAWs) have been studied for a long time due to their intrinsic importance and the many application fields in which they operate. A new subset of SAWs, called foldable SAWs, has recently been discovered when investigating two different SAW manipulations embedded within existing protein structure prediction (PSP) software. Since then, several attempts have been made to find out more about these walks, including counting them. However, calculating the number of foldable SAWs appeared as a tough work, and current supercomputers fail to count foldable SAWs of length exceeding ≈ 30 steps. In this article, we present new progress in this enumeration, bo…
The 1-loop effective potential for the Standard Model in curved spacetime
2018
The renormalisation group improved Standard Model effective potential in an arbitrary curved spacetime is computed to one loop order in perturbation theory. The loop corrections are computed in the ultraviolet limit, which makes them independent of the choice of the vacuum state and allows the derivation of the complete set of $\beta$-functions. The potential depends on the spacetime curvature through the direct non-minimal Higgs-curvature coupling, curvature contributions to the loop diagrams, and through the curvature dependence of the renormalisation scale. Together, these lead to significant curvature dependence, which needs to be taken into account in cosmological applications, which i…
Reconciling tensor and scalar observables in G-inflation
2018
The simple $m^2\phi^2$ potential as an inflationary model is coming under increasing tension with limits on the tensor-to-scalar ratio $r$ and measurements of the scalar spectral index $n_s$. Cubic Galileon interactions in the context of the Horndeski action can potentially reconcile the observables. However, we show that this cannot be achieved with only a constant Galileon mass scale because the interactions turn off too slowly, leading also to gradient instabilities after inflation ends. Allowing for a more rapid transition can reconcile the observables but moderately breaks the slow-roll approximation leading to a relatively large and negative running of the tilt $\alpha_s$ that can be …
Proof II: Lower Bounds
2019
In this chapter we give a lower bound on \(\ln \det S_{\delta ,z}\) which is valid with high probability, and then using also the upper bounds of Chap. 16, we conclude the proof of Theorem 15.3.1 with the help of Theorem 12.1.2.
Quantum search of spatial regions
2003
Can Grover's algorithm speed up search of a physical region - for example a 2-D grid of size sqrt(n) by sqrt(n)? The problem is that sqrt(n) time seems to be needed for each query, just to move amplitude across the grid. Here we show that this problem can be surmounted, refuting a claim to the contrary by Benioff. In particular, we show how to search a d-dimensional hypercube in time O(sqrt n) for d at least 3, or O((sqrt n)(log n)^(3/2)) for d=2. More generally, we introduce a model of quantum query complexity on graphs, motivated by fundamental physical limits on information storage, particularly the holographic principle from black hole thermodynamics. Our results in this model include a…
Transmigración del canino inferior incluido: Presentación de un caso y revisión de la literatura
2006
La retención, es decir, la no erupción de un diente permanente más allá de un año después de la edad normal de erupción, es relativamente poco frecuente si exceptuamos el caso de los terceros molares y los caninos superiores. La transmigración se define como el fenómeno en el cual un diente incluido no erupcionado traspasa en más de la mitad de su longitud la línea media. Exponemos el caso clínico de una paciente de 20 años de edad, que presentaba la transmigración del canino inferior izquierdo, con un patrón de migración tipo 4 de Mupparapu. De igual forma, realizamos una revisión bibliográfica de los casos publicados de transmigración, actualizando los principales aspectos de esta patolog…
On an Inequality for Legendre Polynomials
2020
This paper is concerned with the orthogonal polynomials. Upper and lower bounds of Legendre polynomials are obtained. Furthermore, entropies associated with discrete probability distributions is a topic considered in this paper. Bounds of the entropies which improve some previously known results are obtained in terms of inequalities. In order to illustrate the results obtained in this paper and to compare them with other results from the literature some graphs are provided.
Effects of unconventional monetary policy on income and wealth distribution: Evidence from United States and Eurozone
2019
As an answer to the “Great Recession” and Zero Lower Bound problem, main central banks had to use unconventional monetary policy (UMP). This research focuses on the distributive effects of these measures on household income and household wealth in the United States of America (USA) and the Eurozone. For this purpose, this paper presents four models that were constructed using the Structural Vector Autoregressive methodology (SVAR). The results suggest that the UMPs applied by the Federal Reserve (FED) in the USA could increase wealth and income inequality through the portfolio channel. However, the same results were not observed in the Eurozone. Key words: United States of America, Eurozone…