Article
Astronomy & Astrophysics
Damien Easson, Tucker Manton, Maulik Parikh, Andrew Svesko
Summary: This study explores the relationship between generalized Galileons and Horndeski gravity, showing that a specific subset of Horndeski theories is permitted by string theory. The form of the Galileonic terms is precisely fixed by parameters of the embedding spacetime, indicating a string-theoretic origin for Horndeski theories of gravity. A novel limit of the model is considered by performing a dimensionful rescaling of alpha'.
JOURNAL OF COSMOLOGY AND ASTROPARTICLE PHYSICS
(2021)
Article
Astronomy & Astrophysics
Bartlomiej Kiczek, Marek Rogatko, Karol Wysokinski
Summary: Using the gauge-gravity duality to explore the properties of a holographic superconducting quantum device influenced by dark matter, researchers have observed a small but visible effect on the device's maximal current when a dark matter particle traverses it.
JOURNAL OF COSMOLOGY AND ASTROPARTICLE PHYSICS
(2021)
Article
Astronomy & Astrophysics
Julian Freigang, Dieter Luest, Guo-En Nian, Marco Scalisi
Summary: This study examines the validity of the Swampland Distance Conjecture on prototype geometries of infinite distance limits of Calabi-Yau compactifications and finds that field trajectories leading to cosmic acceleration and featuring rapid turns near the boundary of the moduli space exist in the Swampland. This has significant implications for the realization and consistency of multi-field scenarios in string theory.
JOURNAL OF COSMOLOGY AND ASTROPARTICLE PHYSICS
(2023)
Review
Physics, Multidisciplinary
Marieke van Beest, Jose Calderon-Infante, Delaram Mirfendereski, Irene Valenzuela
Summary: The Swampland program aims to determine the constraints that must be satisfied by an effective field theory to be consistent with a UV embedding in a quantum gravity theory. This article provides a pedagogical introduction to the most important Swampland conjectures, their connections, and their realization in string theory compactifications.
PHYSICS REPORTS-REVIEW SECTION OF PHYSICS LETTERS
(2022)
Article
Astronomy & Astrophysics
Orfeu Bertolami, Paulo M. Sa
Summary: Multi-field cold inflation models are usually at odds with the swampland conjectures in string theory, but can be reconciled in the strong dissipative regime of warm inflation.
JOURNAL OF COSMOLOGY AND ASTROPARTICLE PHYSICS
(2022)
Article
Astronomy & Astrophysics
Min-Seok Seo
Summary: This paper discusses the influence of quantum fluctuations and density fluctuations on black hole production in inflation. It proposes the equivalence between the no eternal inflation condition and the condition that radiation density fluctuations are not sufficient to produce black holes. It also highlights that the information paradox does not arise when the radiation emitted by the horizon does not produce black holes.
JOURNAL OF COSMOLOGY AND ASTROPARTICLE PHYSICS
(2022)
Article
Astronomy & Astrophysics
Vikas Aragam, Roberta Chiovoloni, Sonia Paban, Robert Rosati, Ivonne Zavala
Summary: Strongly non-geodesic, or rapidly turning trajectories in multifield inflation, have recently gained significant attention from both theoretical and phenomenological perspectives. Most existing models with large turning rates are formulated within the framework of effective field theories. This paper investigates rapid-turn inflation in supergravity as an initial step towards understanding them in the context of string theory. The research reveals that large turning rates can be achieved in a wide range of models, but at the expense of high field space curvature. The models satisfy the de Sitter swampland conjecture along the inflationary trajectory, but the high curvatures highlight the challenges in obtaining rapid-turn inflation in realistic string-theoretical models.
JOURNAL OF COSMOLOGY AND ASTROPARTICLE PHYSICS
(2022)
Article
Astronomy & Astrophysics
Omer Guleryuz
Summary: In this work, an effective field theory for string inflation with spontaneously broken supersymmetry is presented, without generating any supersymmetric anti-de Sitter vacua. The analysis of nilpotent superfields effectively captures the physics of anti-D3 branes and reveals a novel uplifting method by adding the same parameter as a complex contribution parallel to the decomposition of a superfield. With almost vanishing cosmological constant in the region where the inflationary attractors unify, the introduction of nilpotent superfields drastically extends the string landscape for the de Sitter (swampland) conjecture.
JOURNAL OF COSMOLOGY AND ASTROPARTICLE PHYSICS
(2023)
Article
Physics, Particles & Fields
Mohammad R. Garousi
Summary: The least action principle states that open spacetime manifolds have data on the boundary. It has recently been proposed that the data for effective actions at order a' are the values of the massless fields and their first derivatives, which must be respected by T-duality transformations at order a'. Moreover, the unit vector to the boundary should not be changed by T-duality transformations, implying invariance of the base space metric. Assuming such restricted T-duality transformations, it has been shown that the transformation of the parity-odd part of the effective action of the heterotic string theory at order a' under the Buscher rules is cancelled by total derivative terms and restricted T-duality transformations at order a'. By using Stokes' theorem, it is then demonstrated that the boundary terms in the base space corresponding to the total derivative terms are exactly cancelled by the transformation of the Gibbons-Hawking boundary term under the above restricted T-duality transformations. These calculations provide confirmation for the proposal of data on the boundary for effective actions at order a'.
EUROPEAN PHYSICAL JOURNAL C
(2023)
Article
Astronomy & Astrophysics
Lerh Feng Low, Richard Easther, Shaun Hotchkiss
Summary: Random, multifield functions can set generic expectations for landscape-style cosmologies. By considering the inflationary implications of a landscape defined by a Gaussian random function, it is shown that the key properties of this landscape depend only on its dimensionality and a single parameter, and the fraction of saddles supporting inflation can be computed, allowing the identification of scenarios resembling our universe.
JOURNAL OF COSMOLOGY AND ASTROPARTICLE PHYSICS
(2022)
Article
Astronomy & Astrophysics
Francesca Chadha-Day
Summary: String theory compactifications may produce numerous light axion-like particles with weak electromagnetic couplings. A linear combination of these particles may have an observable coupling to electromagnetism. However, the basis in which one particle couples to electromagnetism is usually misaligned with the mass basis, resulting in mixing with other hidden particles that do not directly interact with photons. This mixing can substantially reduce the predicted signal in experiments such as the CERN Axion Solar Telescope.
JOURNAL OF COSMOLOGY AND ASTROPARTICLE PHYSICS
(2022)
Article
Astronomy & Astrophysics
Khursid Alam, Koushik Dutta
Summary: This paper studies how the effects of reheating can ease the problem of moduli destabilization. The associated time scale of producing the thermal bath allows for a larger initial field range to stabilize the field. Contrary to the usual notion, a larger initial field range is allowed for higher temperatures when the effective potential is of a run-away nature. This eases the moduli destabilization problem for heavy mass moduli. However, for low mass moduli, the allowed field range still violates the constraints of the cosmological moduli problem unless its initial abundance is suppressed.
JOURNAL OF COSMOLOGY AND ASTROPARTICLE PHYSICS
(2022)
Article
Astronomy & Astrophysics
Ugur Atli, Omer Guleryuz
Summary: This study introduces a bounded de Sitter conjecture for single-field slow-roll inflation theory, incorporating the concepts of supergravity methods, Kahler kinetic terms, and single-field slow-roll inflation parameters.
JOURNAL OF COSMOLOGY AND ASTROPARTICLE PHYSICS
(2021)
Article
Physics, Multidisciplinary
M. J. S. Houndjo, M. G. Ganiou, F. M. Kombetto, J. Tossa
Summary: In this paper, we investigate the f(T) theory of gravity coupled with scalar field and its reconstruction in the context of an exponential evolution of the scale factor. The impact of algebraic function on the slow-roll parameters is analyzed, and the results demonstrate the consistency of the reconstructed model with the recent data.
CHINESE JOURNAL OF PHYSICS
(2022)
Article
Astronomy & Astrophysics
James Page, Joao Magueijo
Summary: This study revisits a mechanism proposed by Hawking to address the cosmological constant problem and offers alternative solutions. By introducing a new action coupling the four-form field strength to the cosmological constant, a novel mechanism similar to Unimodular Gravity is presented. A theory with a similar coupling is also discussed, showing promising results and proposing new interpretations related to time and probability flux.
JOURNAL OF COSMOLOGY AND ASTROPARTICLE PHYSICS
(2021)
Article
Astronomy & Astrophysics
Mar Bastero-Gil, Jose Santiago, Lorenzo Ubaldi, Roberto Vega-Morales
JOURNAL OF COSMOLOGY AND ASTROPARTICLE PHYSICS
(2019)
Article
Astronomy & Astrophysics
Mar Bastero-Gil, Arjun Berera, Jaime R. Calderon
JOURNAL OF COSMOLOGY AND ASTROPARTICLE PHYSICS
(2019)
Article
Astronomy & Astrophysics
Bert Janssen, Alejandro Jimenez-Cano, Jose Alberto Orejuela
Article
Astronomy & Astrophysics
Bert Janssen, Alejandro Jimenez-Cano
Article
Computer Science, Interdisciplinary Applications
Salvador Vidal-Bravo, Javier De La Cruz, Mario Roberto Arrieta Paternina, Monica Borunda, Alejandro Zamora-Mendez
COMPUTER APPLICATIONS IN ENGINEERING EDUCATION
(2020)
Article
Green & Sustainable Science & Technology
Monica Borunda, Raul Garduno-Ramirez, O. A. Jaramillo
Article
Multidisciplinary Sciences
Monica Borunda, Javier de la Cruz, Raul Garduno-Ramirez, Ann Nicholson
Article
Astronomy & Astrophysics
Mar Bastero-Gil, Arjun Berera, Rudnei O. Ramos, Joao G. Rosa
Summary: This study introduces the first quantum field theory model of inflation that is renormalizable in the matter sector and shows that strong dissipation can sustain a slow-roll trajectory in warm inflation. The dissipation coefficient decreases with temperature, preventing a large growth of thermal inflaton fluctuations.
Article
Astronomy & Astrophysics
Mar Bastero-Gil, Antonio Torres Manso
Summary: We present a supersymmetric extension of a unified model for inflation and Dark Matter, which is based on the incomplete decay of the inflaton field into right-handed neutrino pairs. By imposing a discrete interchange symmetry on the inflaton and right-handed neutrinos, stability of the inflaton field at the global minimum is ensured, while still allowing partial decay and reheating of the Universe. Compatibility with inflationary predictions, BBN bounds, and obtaining the right DM abundance typically requires large couplings to the neutrino sector.
JOURNAL OF COSMOLOGY AND ASTROPARTICLE PHYSICS
(2021)
Article
Astronomy & Astrophysics
Mar Bastero-Gil, Cyprien Beaufort, Daniel Santos
Summary: This study discusses the production of KK axions in the Sun and proposes a model as a possible explanation for the non-thermal distribution of solar X-rays, indicating that KK axions may escape EBL constraints. By analyzing recent measurements of solar luminosity, it is found that the decay event rate for KK axions is significantly lower than previously thought.
JOURNAL OF COSMOLOGY AND ASTROPARTICLE PHYSICS
(2021)
Article
Astronomy & Astrophysics
Mar Bastero-Gil, Marta Subias Diaz-Blanco
Summary: Research shows that in some warm inflation models, interactions with other light degrees of freedom can enhance the primordial spectrum during the final stages of inflation and lead to the formation of evaporating Primordial Black Holes. These fluctuations also act as a source for tensors at second order and peak near the end of inflation, resulting in a spectral density of Gravitational Waves with frequencies around O(10^5 - 10^6) Hz and an amplitude of around 10^-9.
JOURNAL OF COSMOLOGY AND ASTROPARTICLE PHYSICS
(2021)
Article
Astronomy & Astrophysics
Mar Bastero-Gil, Jose Santiago, Roberto Vega-Morales, Lorenzo Ubaldi
Summary: We study a mechanism for producing dark photon dark matter at the end of inflation. The rolling inflaton induces a tachyonic instability, leading to the coherent production of dark gauge bosons. We examine the case where the dark photons are relativistic when their mass is generated and calculate the relic abundance today. Furthermore, we analyze the late time power spectrum and find that it preserves the peak generated at the end of inflation.
JOURNAL OF COSMOLOGY AND ASTROPARTICLE PHYSICS
(2022)
Article
Energy & Fuels
Monica Borunda, Adrian Ramirez, Raul Garduno, Gerardo Ruiz, Sergio Hernandez, O. A. Jaramillo
Summary: This paper proposes a fast-track methodology to address the requirements of site selection and energy forecasting for solar PV plants. The methodology retrieves solar radiation and temperature data, clusters the region of interest into land cells, and maps them based on solar resources. PV energy calculation and forecasting are also conducted. The proposed methodology is validated with actual PV plant generation.
Article
Astronomy & Astrophysics
Mar Bastero-Gil, Arjun Berera, Rafael Hernandez-Jimenez, Joao G. Rosa
Article
Astronomy & Astrophysics
Mar Bastero-Gil, Arjun Berera, Rafael Hernandez-Jimenez, Joao G. Rosa