Slepian models for Gaussian random landscapes

Phenomenologically interesting scalar potentials are highly atypical in generic random landscapes. We develop the mathematical techniques to generate constrained random potentials, i.e.Slepian models, which can globally represent low-probability realizations of the landscape. We give analytical as well as numerical methods to construct these Slepian models for constrained realizations of a full Gaussian random field around critical as well as inflection points. We use these techniques to numerically generate in an efficient way a large number of minima at arbitrary heights of the potential and calculate their non-perturbative decay rate. Furthermore, we also illustrate how to use these methods by obtaining statistical information about the distribution of observables in an inflationary inflection point constructed within these models.We are grateful to Alex Vilenkin, Masaki Yamada and Jeremy M. Wachter for useful discussions, and to Jonathan Frazer for discussions and collaboration at the early stages of this project. This work was supported in part by the Spanish Ministry MINECO grant (FPA2015-64041-C2-1P), the MCIU/AEI/FEDER grant (PGC2018-094626-B-C21), the Basque Government grant (IT-979-16), the University of the Basque Country grant (PIF17/74), the Basque Foundation for Science (IKERBASQUE) and the Czech science foundation GA ~ CR grant (19-01850S). The numerical work necessary to carry out this research has been possible thanks to the computing infrastructure of the ARINA cluster at the University of the Basque Country, UPV/EHU

Universal class of type-IIB flux vacua with analytic mass spectrum

We report on a new class of flux vacua generically present in Calabi-Yau compactifications of type-IIB string theory. At these vacua, the mass spectrum of the complete axiodilaton/complex structure sector is given, to leading order in a' and g(s), by a simple analytic formula independent of the choice of Calabi-Yau. We provide a method to find these vacua and construct an ensemble of 17,054 solutions for the Calabi-Yau hypersurface WP[1,1,1,6,9]4, where the masses of the axiodilaton and the 272 complex structure fields can be explicitly computed.This work is supported by the Spanish Ministry MCIU/AEI/FEDER Grant No. PGC2018-094626-B-C21, the Basque Government Grant No. IT-979-16, and the Basque Foundation for Science (IKERBASQUE). K. S. is supported by the Czech science foundation GACR Grant No. 19-01850S. M. A. U. is also supported by the University of the Basque Country Grant No. PIF17/74. For the numerical work, we used the computing infrastructure of the ARINA cluster at the University of the Basque Country (UPV/EHU)

Towards a Complete Mass Spectrum of Type-IIB Flux Vacua at Large Complex Structure

The large number of moduli fields arising in a generic string theory compactification makes a complete computation of the low energy effective theory infeasible. A common strategy to solve this problem is to consider Calabi-Yau manifolds with discrete symmetries, which effectively reduce the number of moduli and make the computation of the truncated Effective Field Theory possible. In this approach, however, the couplings (e.g., the masses) of the truncated fields are left undetermined. In the present paper we discuss the tree-level mass spectrum of type-IIB flux compactifications at Large Complex Structure, focusing on models with a reduced one-dimensional complex structure sector. We compute the tree-level spectrum for the dilaton and complex structure moduli, including the truncated fields, which can be expressed entirely in terms of the known couplings of the reduced theory. We show that the masses of this set of fields are naturally heavy at vacua consistent with the KKLT construction, and we discuss other phenomenologically interesting scenarios where the spectrum involves fields much lighter than the gravitino. We also derive the probability distribution for the masses on the ensemble of flux vacua, and show that it exhibits universal features independent of the details of the compactification. We check our results on a large sample of flux vacua constructed in an orientifold of the Calabi-Yau WP[1,1,1,1,4]4. Finally, we also discuss the conditions under which the spectrum derived here could arise in more general compactifications

Excited Abelian-Higgs vortices: Decay rate and radiation emission

The evolution of 1 vortices when their massive bound mode is excited is investigated in detail (both analytically and numerically) in the Abelian-Higgs model for different ranges of the self-coupling constant. The dependence of the spectrum of the 1 vortex fluctuation operator on the model parameter is discussed initially. A perturbative approach is employed to study the radiation emission in both the scalar and the vector channels. Our findings reveal that the oscillating initial configuration of the 1 vortex radiates at a frequency twice that of the internal mode. Through energy conservation considerations, we derive the decay law of the massive mode. Finally, these analytical results are compared with numerical simulations in field theory.. This research was supported in part by Spanish MCIN with funding from European Union NextGenerationEU (PRTRC17.I1) and Consejeria de Educacion from JCyL through QCAYLE project, as well as MCIN Project No. PID2020–113406 GB-I00. D. M. C. and S. N. O. acknowledge financial support from the European Social Fund, the Operational Programme of Junta de Castilla y Leon and the regional Ministry of Education. J. J. B.-P. has been supported in part by Grant No. PID2021-53123703NB-C21 funded by MCIN/AEI/ 10.13039/501100011033/ and by ERDF; “A way of making Europe”; the Basque Government (Grant No. IT- 1628-22) and the Basque Foundation for Science (IKERBASQUE)

Vocabulario de la sociedad civil, la ruralidad y los movimientos sociales en América Latina

El Vocabulario de la Sociedad Civil, la Ruralidad y los Movimientos Sociales en América Latina tiene como objetivo desarrollar vocablos relacionados con temas de gran trascendencia para la vida colectiva de la población Latinoamericana; pretende introducir a estudiantes, personas del ámbito académico y activistas en la comprensión de estas categorías de análisis. A través de la mirada de 70 especialistas que participaron en este vocabulario, es posible comprender muchos de los términos que se utilizan dentro de la investigación social y áreas relacionadas con las ciencias políticas, ambientales y rurales, a partir de una mayor explicación y detalle. Es por ello que se inserta este trabajo desde una mirada colectiva y amplia de los conceptos que se exponen. En este libro podrá encontrar las ideas de varios autores y autoras de distintas universidades, con una visión multi, inter y transdisciplinaria. El esfuerzo que se realizó para conjuntar varios términos y analizar su compleja red de interpretaciones, permitirá que este manuscrito pueda ser consultado por estudiantes, personas del ámbito científico-académico, y ciudadanía; porque contiene el estado del arte, la historia del paulatino avance de múltiples conceptos y su vigencia en el contexto actual

Brane nucleation in supersymmetric models

This paper explores the process of vacuum decay in supersymmetric models related to flux compactifications. In particular, we describe these instabilities within supersymmetric Lagrangians for a single three-form multiplet. This multiplet combines scalar fields, representing the moduli fields in four dimensions, with 3-form fields that influence the potential for these moduli via the integer flux of their associated 4-form field strength. Furthermore, using supersymmetry as a guide we obtain the form of the couplings of these fields to the membranes that act as sources to the 3-form potentials. Adding small supersymmetry breaking terms to these Lagrangians one can obtain instanton solutions describing the decay of the vacua in these models by the formation of a membrane bubble. These instantons combine the usual Coleman-de Luccia and the Brown-Teitelboim formalisms in a single unified model. We study simple numerical examples of theories with and without gravity in this new framework and generalize known Euclidean methods to accomodate the simulataneous inclusion of scalar fields and charged membranes to these instanton solutions. Moreover, we show explicitly in these examples how one recovers the static supersymmetric solutions in the limiting case where the supersymmetry breaking terms vanish. In this limit, the bubble becomes infinite and flat and represents a hybrid between the usual supersymmetric domain walls of field theory models and the brane solutions interpolating between the supersymmetric vacua; a sort of dressed supermembrane BPS solution. Finally, we briefly comment on the implications of these solutions in cosmological models based on the String Theory Landscape where these type of 4d effective theories could be relevant in inflationary scenarios.We are grateful to Thibaut Coudarchet for interesting discussions. This study is supported in part by the PID2021-123703NB-C21 and PID2021-125700NB-C21 (IB) grants funded by MCIN/ AEI /10.13039/501100011033/ and by ERDF; “A way of making Europe”, the Basque Government grant (IT-1628-22) and the Basque Foundation for Science (IKER-BASQUE)

Nambu-Goto Dynamics of Field Theory Cosmic String Loops

We perform a detailed comparison of the dynamics of cosmic string loops obtained in cosmological field theory simulations with their expected motion according to the Nambu-Goto action. We demonstrate that these loops follow the trajectories predicted within the NG effective theory except in regions of high curvature where energy is emitted from the loop in the form of massive radiation. This energy loss continues for all the loops studied in this simulation until they self-intersect or become small enough that they annihilate and disappear well before they complete a single oscillation. We comment on the relevance of this investigation to the interpretation of the results from cosmological field theory simulations as well as their extrapolation to a cosmological context

Cosmology with the Laser Interferometer Space Antenna

The Laser Interferometer Space Antenna (LISA) has two scientific objectives of cosmological focus: to probe the expansion rate of the universe, and to understand stochastic gravitational-wave backgrounds and their implications for early universe and particle physics, from the MeV to the Planck scale. However, the range of potential cosmological applications of gravitational wave observations extends well beyond these two objectives. This publication presents a summary of the state of the art in LISA cosmology, theory and methods, and identifies new opportunities to use gravitational wave observations by LISA to probe the universe

Cosmology with the Laser Interferometer Space Antenna

The Laser Interferometer Space Antenna (LISA) has two scientific objectives of cosmological focus: to probe the expansion rate of the universe, and to understand stochastic gravitational-wave backgrounds and their implications for early universe and particle physics, from the MeV to the Planck scale. However, the range of potential cosmological applications of gravitational wave observations extends well beyond these two objectives. This publication presents a summary of the state of the art in LISA cosmology, theory and methods, and identifies new opportunities to use gravitational wave observations by LISA to probe the universe

Cosmology with the Laser Interferometer Space Antenna

The Laser Interferometer Space Antenna (LISA) has two scientific objectives of cosmological focus: to probe the expansion rate of the universe, and to understand stochastic gravitational-wave backgrounds and their implications for early universe and particle physics, from the MeV to the Planck scale. However, the range of potential cosmological applications of gravitational wave observations extends well beyond these two objectives. This publication presents a summary of the state of the art in LISA cosmology, theory and methods, and identifies new opportunities to use gravitational wave observations by LISA to probe the universe