Higgs-otic Inflation and Moduli Stabilization

We study closed-string moduli stabilization in Higgs-otic inflation in Type IIB orientifold backgrounds with fluxes. In this setup large-field inflation is driven by the vacuum energy of mobile D7-branes. Imaginary selfdual (ISD) three-form fluxes in the background source a $\mu$-term and the necessary monodromy for large field excursions while imaginary anti-selfdual (IASD) three-form fluxes are sourced by non-perturbative contributions to the superpotential necessary for moduli stabilization. We analyze K\"ahler moduli stabilization and backreaction on the inflaton potential in detail. Confirming results in the recent literature, we find that integrating out heavy K\"ahler moduli leads to a controlled flattening of the inflaton potential. We quantify the flux tuning necessary for stability even during large-field inflation. Moreover, we study the backreaction of supersymmetrically stabilized complex structure moduli and the axio-dilaton in the K\"ahler metric of the inflaton. Contrary to previous findings, this backreaction can be pushed far out in field space if a similar flux tuning as in the K\"ahler sector is possible. This allows for a trans-Planckian field range large enough to support inflation.Comment: 42 pages, 10 figures, v2: comments and references added. Published versio

The DBI Action, Higher-derivative Supergravity, and Flattening Inflaton Potentials

In string theory compactifications it is common to find an effective Lagrangian for the scalar fields with a non-canonical kinetic term. We study the effective action of the scalar position moduli of Type II D$p$-branes. In many instances the kinetic terms are in fact modified by a term proportional to the scalar potential itself. This can be linked to the appearance of higher-dimensional supersymmetric operators correcting the K\"ahler potential. We identify the supersymmetric dimension-eight operators describing the $\alpha'$ corrections captured by the D-brane Dirac-Born-Infeld action. Our analysis then allows an embedding of the D-brane moduli effective action into an $\mathcal N = 1$ supergravity formulation. The effects of the potential-dependent kinetic terms may be very important if one of the scalars is the inflaton, since they lead to a flattening of the scalar potential. We analyze this flattening effect in detail and compute its impact on the CMB observables for single-field inflation with monomial potentials.Comment: 25 pages, 3 figures. Comments and references added. Published versio

From semantic underdetermination via metaphor and metonymy to conceptual interaction

The question of semantic underdetermination is related to the distinction between what is said and what is implicated. In this paper we examine the relevance-theoretic notion of enrichment as a procedure for developing what is said into a fully specified proposition or explicature. We make the claim that there are two forms of such a procedure, viz. grammatically-motivated and conceptually-motivated enrichment, and discuss their role in communication. We further contend that the notion of enrichment and the other procedures of propositional development recognized in the relevance-theoretic literature are insufficient to account for all cases of explicated meaning. In this connection, we propose other cognitive mechanisms such as mitigation and more interestingly-metaphoric and metonymic mappings. This discussion allows us to cast some light on the implicature/explicature division line and to rank as explicatures some cases of inferences which have so far been considered as implicatures, including those where metaphor and metonymy are involved. Finally we examine the role of metaphoric and metonymic mappings - both in isolation and as part of conceptual interaction systems - in the production of explicatures, which allows us to understand better the communicative potential of these cognitive mechanisms

On the Credibility of the Irish Pound in the EMS

This paper assesses the degree of credibility of the Irish Pound in the European Monetary System between 1983 and 1997. Different credibility indicators proposed in the literature are used to measure agents’ perceptions of the credibility of the ERM commitment in an attempt to distinguish between events stemming from problems in the ERM itself and those that appear to have been exclusive to Ireland.

Calibrating the Dynamic Nelson-Siegel Model: A Practitioner Approach

The dynamic version of the Nelson-Siegel model has shown useful applications in the investment management industry. These applications go from forecasting the yield curve to portfolio risk management. Because of the complexity in the estimation of the parameters, some practitioners are unable to benefit from the uses of this model. In this note we present two approximations to estimate the time series of the model's factors. The first one has a more technical aim, focusing on the construction of a representative base to work, and uses a genetic algorithm to face the optimization problem. The second approximation has a practitioner spirit, focusing on the easiness of implementation. The results show that both approximations have good fitting for the U.S. Treasury bonds market

Calibrating the Dynamic Nelson-Siegel Model: A Practitioner Approach

The dynamic version of the Nelson-Siegel model has shown useful applications in the investment management industry. These applications go from forecasting the yield curve to portfolio risk management. Because of the complexity in the estimation of the parameters, some practitioners are unable to benefit from the uses of this model. In this note we present two approximations to estimate the time series of the model's factors. The first one has a more technical aim, focusing on the construction of a representative base to work, and uses a genetic algorithm to face the optimization problem. The second approximation has a practitioner spirit, focusing on the easiness of implementation. The results show that both approximations have good fitting for the U.S. Treasury bonds market

Entanglement of low-energy excitations in Conformal Field Theory

In a quantum critical chain, the scaling regime of the energy and momentum of the ground state and low lying excitations are described by conformal field theory (CFT). The same holds true for the von Neumann and Renyi entropies of the ground state, which display a universal logarithmic behaviour depending on the central charge. In this letter we generalize this result to those excited states of the chain that correspond to primary fields in CFT. It is shown that the n-th Renyi entropy is related to a 2n-point correlator of primary fields. We verify this statement for the critical XX and XXZ chains. This result uncovers a new link between quantum information theory and CFT.Comment: 4 pages, 3 figure

The clustering of galaxies in the completed SDSS-III Baryon Oscillation Spectroscopic Survey: a tomographic analysis of structure growth and expansion rate from anisotropic galaxy clustering

We perform a tomographic analysis of structure growth and expansion rate from the anisotropic galaxy clustering of the combined sample of Baryon Oscillation Spectroscopic Survey (BOSS) Data Release 12, which covers the redshift range of $0.2<z<0.75$. In order to extract the redshift information of anisotropic galaxy clustering, we analyse this data set in nine overlapping redshift slices in configuration space and perform the joint constraints on the parameters $(D_V, F_{\mathrm{AP}}, f\sigma_8)$ using the correlation function multipoles. The analysis pipeline is validated using the MultiDark-Patchy mock catalogues. We obtain a measurement precision of $1.5\%-2.9\%$ for $D_V$, $5.2\%-9\%$ for $F_{\mathrm{AP}}$ and $13.3\%-24\%$ for $f \sigma_8$, depending on the effective redshift of the slices. We report a joint measurement of $(D_V, F_{\mathrm{AP}}, f\sigma_8)$ with the full covariance matrix in nine redshift slices. We use our joint BAO and RSD measurement combined with external datasets to constrain the gravitational growth index $\gamma$, and find $\gamma=0.656 \pm 0.057$, which is consistent with the $\Lambda$CDM prediction within 95\% CL.Comment: 8 pages, 8 figures, 2 tables, accepted for publication MNRAS. The measured results including the full covariance matrices are made available at https://github.com/ytcosmo/TomoBAORSD and tomographic clustering data used in this work is available at https://sdss3.org//science/boss_publications.ph

Incorporating Market Regimes into Large-Scale Stock Portfolios: A Hidden Markov Model Approach

We propose a portfolio construction method that accounts for the regime-dependent behavior of stocks, thereby impacting their expected returns. Using a hidden Markov model (HMM) and a regime-weighted least-squares approach, we estimate forward-looking regime-conditional factors. These factors help build large-scale stock portfolios for systematic investment management, considering financial market regimes. In historical simulations, our framework achieves superior risk-adjusted performance compared to passive portfolios in both relative and absolute management settings