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M. Moriconi

Publications and source records attributed to M. Moriconi.

At least 19 recordsLinked to original sources
arXiv2026

Detection and characterization of the temperate super-earth Gliese 48 b

Gliese 48 is an M3.5V red dwarf exhibiting significant magnetic activity and a stellar rotation period of 51.5 d. In this work, we present a systematic re-analysis of radial velocities (RV) from CARMENES and decade-long HIRES observations, integrated with TESS space-based photometry. We identify a planet of undetermined composition, Gliese 48 b, with an orbital period $P = 39.6299 \pm 0.29$ d and a minimum mass $M \sin i = 8.11 \pm 1.63 M_{\oplus}$. The planetary nature of the signal is confirmed by its temporal coherence over a 15-year baseline and its achromaticity between visible and near-infrared channels. TESS photometry from Sectors 18, 19, 24, and 25 (218.6 d total baseline, 66,983 cadences) reveals no transit at $P = 39.63$ d (FAP $> 10\%$, BLS). An injection-and-recovery test demonstrates that a 1287 ppm transit signal corresponding to a minimum-radius $1.69 R_{\oplus}$ planet would have been detected with Signal-to-Pink-Noise Ratio SPNR $> 7$, ruling out a transiting geometry with high confidence. The orbital inclination is constrained to $i < 89.3^{\circ}$. With an incident stellar flux $S_{\rm eff} \approx 0.889 S_{\oplus}$ and bolometric luminosity $L_* = 0.0273 \pm 0.0023 L_{\odot}$, Gliese 48 b lies near the inner edge of the Conservative Habitable Zone and within the Optimistic HZ, making it one of the most astrobiologically compelling temperate Super-Earths orbiting an M-dwarf.

astro-ph.EP↗
arXiv2024

TIC 393818343 c: Discovery and characterization of a Neptune-like planet in the Delphinus constellation

We report on the statistical confirmation of a second planet inside the TIC 393818343 system. The first planet TIC 393818343 b has been confirmed and classified as a Warm Jupiter planet with a period of P = (16.24921 +- 0.00003) days. The second planet in the system has an orbital period of P = (7.8458 +- 0.0023) days and orbits 2.05 times closer to its host star. The second planet was initially spotted by the Las Cumbres Observatory (LCOGT) and amateur astronomers. This Super-Neptunian exoplanet marks TIC 393818343 as a multi-planetary system.

astro-ph.EP↗
arXiv2023

Candidate triple-star system with ellipsoidal components detected in Vulpecula through TESS photometry

MaGiV-1 is a candidate triple ellipsoidal star system in Vulpecula at coordinates RA(J2000) 19:52:19.13 DEC(J2000) +23:29:59.7 classified as ELL+ELL, number 2344411 in AAVSO VSX database. Through photometry from the TESS Space Telescope, two significant periods describing the orbital times of the components were identified using the Fourier transform. The analysis led to determining P(A-BC) = 4.269d the orbital period of A-BC pair, the primary component with the secondary component described by another pair, and P(BC) = 0.610d the orbital period of B-C pair, the inner ellipsoidal system. However, it cannot be completely ruled out that the shorter period can be explained by pulsations of one of the two components (e.g. by the GDOR type).

astro-ph.SR↗
arXiv2022

New Semiregular Variable Star Near The Wizard Nebula -- Evolution of the Red Giant MACOMP_V1

The red giant MaCoMP_V1 in Cepheus at coordinates RA (J2000) 22:49:05:49 and DEC (J2000) +57:52:41:6 is a semiregular variable star classified as SRS, number 2225960 in the AAVSO VSX database. Using the Fourier transform, the period P = 24.751(0.062)d was evaluated and, with the support of the ASAS-SN and ZTF surveys, a well-defined light curve was made. The analysis resulted in the fundamental physical parameters of MaCoMP_V1, such as the mass M = 4.97(0.38)M(Sun) and radius R = 40.5(6.7)R(Sun), with consistent values suggesting the characteristics of a semiregular red giant. In addition, the effective temperature Teff = 4500(135)K from the Gaia catalog and the stellar evolution based on the Schoenberg-Chandraskehar limit was estimated.

astro-ph.SR↗
arXiv2010

Conformal Invariance in (2+1)-Dimensional Stochastic Systems

Stochastic partial differential equations can be used to model second order thermodynamical phase transitions, as well as a number of critical out-of-equilibrium phenomena. In (2+1) dimensions, many of these systems are conjectured (and some are indeed proved) to be described by conformal field theories. We advance, in the framework of the Martin-Siggia-Rose field theoretical formalism of stochastic dynamics, a general solution of the translation Ward identities, which yields a putative conformal energy-momentum tensor. Even though the computation of energy-momentum correlators is obstructed, in principle, by dimensional reduction issues, these are bypassed by the addition of replicated fields to the original (2+1)-dimensional model. The method is illustrated with an application to the Kardar-Parisi-Zhang (KPZ) model of surface growth. The consistency of the approach is checked by means of a straightforward perturbative analysis of the KPZ ultraviolet region, leading, as expected, to its $c=1$ conformal fixed point.

cond-mat.stat-mech↗
arXiv2009

How to get rid of Dirac worldsheets in the Cho-Fadeev-Niemi representation of SU(2) Yang-Mills theory

In this paper, we present an exact procedure to deal with Dirac strings or worldsheets in gauge theories containing ensembles of monopoles interacting with charged fields. For SU(2) Yang-Mills theory, initially we construct the appropriate change of variables of the charged fields (including charged ghosts and auxiliary fields) so that the only change in the integrand of the partition function, in the Maximal Abelian gauge, is the addition of given closed Dirac worldsheets. Next, we derive our main result, namely, we show that it is always possible to choose them in such a manner that the total (open plus closed) Dirac worldsheets explicitly decouple from the charged sector, leaving only the effect of their associated gauge invariant borders (where the monopoles are placed), without missing any information about the center vortex sector. This procedure serves as a simplifying basis to deal with ensembles of monopoles and center vortices in the framework of the Cho-Faddeev-Niemi gauge field decomposition, by writing the partition function only in terms of the physical part of the defects to be integrated.

hep-th↗
arXiv2007

Nodes of Wavefunctions

We give a simple argument to show that the $n$th wavefunction for the one-dimensional Schrödinger equation has $n-1$ nodes. We also show that if $n_1 < n_2$, then between two consecutive zeros of $ψ_{n_1}$, there is a zero of $ψ_{n_2}$.

quant-ph↗
arXiv2006

Special Theory of Relativity through the Doppler Effect

We present the special theory of relativity taking the Doppler effect as the starting point, and derive several of its main effects, such as time dilation, length contraction, addition of velocities, and the mass-energy relation, and assuming energy and momentum conservation, we discuss how to introduce the 4-momentum in a natural way. We also use the Doppler effect to explain the "twin paradox", and its version on a cylinder. As a by-product we discuss Bell's spaceship paradox, and the Lorentz transformation for arbitrary velocities in one dimension.

physics.class-ph↗
arXiv2005

Non-perturbative approach to backscattering off a dynamical impurity in 1D Fermi systems

We investigate the problem of backscattering off a time-dependent impurity in a one-dimensional electron gas. By combining the Schwinger-Keldysh method with an adiabatic approximation in order to deal with the corresponding out of equilibrium Dirac equation, we compute the total energy density (TED) of the system. We show how the free fermion TED is distorted by the backscattering amplitude and the geometry of the impurity.

cond-mat.mes-hall↗
arXiv2005

Bosonic Theory with a Random Defect Line

We study a two-dimensional bosonic field theory with a random defect line. The theory has a background field coupled to the field variables at the defect line, which renders the model non-integrable. However, as the background field is random, and the disorder is implemented through the replica trick, the model becomes integrable, allowing us to use the form-factor method to compute the exact correlation functions of the quenched model.

hep-th↗
arXiv2005

Langevin Simulation of the Chirally Decomposed Sine-Gordon Model

A large class of quantum and statistical field theoretical models, encompassing relevant condensed matter and non-abelian gauge systems, are defined in terms of complex actions. As the ordinary Monte-Carlo methods are useless in dealing with these models, alternative computational strategies have been proposed along the years. The Langevin technique, in particular, is known to be frequently plagued with difficulties such as strong numerical instabilities or subtle ergodic behavior. Regarding the chirally decomposed version of the sine-Gordon model as a prototypical case for the failure of the Langevin approach, we devise a truncation prescription in the stochastic differential equations which yields numerical stability and is assumed not to spoil the Berezinskii-Kosterlitz-Thouless transition. This conjecture is supported by a finite size scaling analysis, whereby a massive phase ending at a line of critical points is clearly observed for the truncated stochastic model.

cond-mat.stat-mech↗
arXiv2003

Non Commutative Field Theories and Integrable Models in 2d

We study the noncommutative extensions of certain integrable field theories, namely the sine- and sinh-Gordon (sG and shG) models, and the U(N) principal chiral model (pcm). We argue that the Moyal deformations of the sG and shG models are not integrable, by looking at tree-level amplitudes where there is particle production. By considering the noncommutative generalization of the zero-curvature method, it is possible to define integrable versions of the noncommutative sG and shG models, which introduce extra constraints. The noncommutative pcm is shown to be integrable and we discuss the existence of non-trivial non-local conserved charges, and the associated noncommutative zero-curvature condition.

hep-th↗
arXiv2003

Noncommutative Integrable Field Theories in 2d

We study the noncommutative generalization of (euclidean) integrable models in two-dimensions, specifically the sine- and sinh-Gordon and the U(N) principal chiral models. By looking at tree-level amplitudes for the sinh-Gordon model we show that its na\"ıve noncommutative generalization is {\em not} integrable. On the other hand, the addition of extra constraints, obtained through the generalization of the zero-curvature method, renders the model integrable. We construct explicit non-local non-trivial conserved charges for the U(N) principal chiral model using the Brezin-Itzykson-Zinn-Justin-Zuber method.

hep-th↗
arXiv2001

Integrable Boundary Conditions and Reflection Matrices for the O(N) Nonlinear Sigma Model

We find new integrable boundary conditions, depending on a free parameter $g$, for the O(N) nonlinear $σ$ model, which are of nondiagonal type, that is, particles can change their ``flavor'' through scattering off the boundary. These boundary conditions are derived from a microscopic boundary lagrangian, which is used to establish their integrability, and exhibit integrable flows between diagonal boundary conditions investigated earlier. We solve the boundary Yang-Baxter equation, connect these solutions to the boundary conditions, and examine the corresponding integrable flows.

hep-th↗
arXiv2001

On the Beta Function for Anisotropic Current Interactions in 2D

By making use of current-algebra Ward identities we study renormalization of general anisotropic current-current interactions in 2D. We obtain a set of algebraic conditions that ensure the renormalizability of the theory to all orders. In a certain minimal prescription we compute the beta function to all orders.

hep-th↗