Optimization of an adaptive thermal lensing device for ground-based gravitational waves interferometers

The project of this thesis stems from a collaboration with the University of Florida lasting two months. The purpose is to design and test a new prototype of an adaptive thermal lensing device for ground-based gravitational waves interferometers, starting from the previously developed in the american university in 2015. Firstly, I will briefly introduce what gravitational waves are and how we have been able to detect them since September 2015, focusing the attention on the american LIGO interferometers, their current noise limits and how they will be upgraded in the next few years, exploiting squeezed light states to shape the quantum vacuum. Throughout the first chapter it will be clear that, in such a context, an adaptive thermal lensing device is an excellent way to allow the implementation of the squeezing. Then to create the theoretical base required to understand the work, it is necessary to introduce lasers, optical cavities, thermal lensing and the so-called mismatch problem. Moving to the actual work, I will describe the previous devices built at the University of Florida, analyzing their strengths, weaknesses and, starting from the latter, the reasons why a new prototype was needed and what improvement we tried to achieve with it. After portraying the new characteristics of my device, I will relate the data collected from some tests run on it and from an actual focal power change experiment. Finally, I will draw the conclusions on the efficiency and functionalities of my work based on the aforementioned data, trying to forecast its future.ope

Updated constraints on amplitude and tilt of the tensor primordial spectrum

We have taken a comprehensive approach to update the limits on the tensor-to-scalar ratio ($r$) and the tensor spectral index ($n_t$), using 10 datasets from the BICEP/Keck Array 2015 and 2018, Planck releases 3 and 4, and LIGO-Virgo-KAGRA Collaboration. By fitting the complete $\Lambda$CDM+$r$+$n_t$ model with two different approaches for the tensor sector, we have not only established which method is the most reliable, but have also achieved the strongest constraint on the tensor-to-scalar ratio in current literature: $r<0.028$ and $-1.37 < n_t < 0.42$ at 95% confidence level. Furthermore, our examination of the common signal detected by the NANOGrav Collaboration further confirms that a simple power-law cannot reconcile the constraints from different datasets if the NANOGrav detection is due to a primordial inflationary gravitational wave background, as previously shown in the literature.Comment: Version coherent with published one. Added new analysis in section 2.4. Added new section 5.1. Added appendix B. Conclusions unchange

Unraveling the CMB lack-of-correlation anomaly with the cosmological gravitational wave background

Since the very first observations, the Cosmic Microwave Background (CMB) has revealed on large-scales unexpected features known as anomalies, which challenge the standard $\Lambda$ cold dark matter ($\Lambda$CDM) cosmological model. One such anomaly is the ``lack-of-correlation'', where the measured two-point angular correlation function of CMB temperature anisotropies is compatible with zero, differently from the predictions of the standard model. This anomaly could indicate a deviation from the standard model, unknown systematics, or simply a rare realization of the model itself. In this study, we explore the possibility that the lack-of-correlation anomaly is a consequence of living in a rare realization of the standard model, by leveraging the potential information provided by the cosmological gravitational wave background (CGWB) detectable by future gravitational wave (GW) interferometers. We analyze both constrained and unconstrained realizations of the CGWB to investigate the extent of information that GWs can offer. To quantify the impact of the CGWB on the lack-of-correlation anomaly, we employ established estimators and introduce a new estimator that addresses the ``look-elsewhere'' effect. Additionally, we consider three different maximum multipoles, denoted as $\ell_{\rm max}$, to account for the anticipated capabilities of future GW detectors ($\ell_{\rm max} = 4, 6, 10$). Summarizing our findings for the case of $\ell_{\rm max} = 4$, we identify the angular range $[63^\circ - 180^\circ]$ as the region where future observations of the CGWB maximize the probability of rejecting the standard model. Furthermore, we calculate the expected significance of this observation, demonstrating that 98.81% (81.67%) of the GW realizations enhance the current significance of the anomaly when considering the full-sky (masked) Planck SMICA map as our CMB sky

Long-range electronic communication in free-base meso-poly(ferrocenyl)-containing porphyrins

H_2FcPh_3P [FcPh_3P = 5-ferrocenyl-10,15,20-triphenyl porphyrin(2-)], cis-H_2Fc_2Ph_2P [cis-Fc_2Ph_2P = 5,10-bisferrocenyl-15,20-diphenyl porphyrin(2-)], trans-H_2Fc_2Ph_2P [trans-Fc_2Ph_2P = 5,15-bisferrocenyl-10,20-diphenyl porphyrin(2-)], and H_2Fc_3PhP [Fc_3PhP = 5,10,15-trisferrocenyl-20-phenyl porphyrin(2-)] along with H_2TPP [TPP = 5,10,15,20-tetraphenylporphyrin] and H_2TFcP [TFcP = 5,10,15,20-tetraferrocenyl porphyrin(2-)] were isolated from the direct cross-condensation reaction between pyrrole, benzaldehyde, and ferrocene carboxaldehyde or from the reaction between ferrocenyl-2,2'-dipyrromethane and benzaldehyde, suggesting a scrambling reaction mechanism for the last approach. All compounds were characterized by UV-vis, MCD, and NMR spectroscopy; APCI MS and MS/MS methods; as well as high-resolution ESI MS spectrometry. The conformational flexibility of ferrocene substituents in all compounds was confirmed using variable-temperature NMR and computational methods. DFT calculations were employed to understand the degree of nonplanarity of the porphyrin core as well as the electronic structure of ferrocene-containing porphyrins. In all cases, a set of occupied, predominantly ferrocene-based molecular orbitals was found between the highest occupied and the lowest unoccupied, predominantly porphyrin-based molecular pi orbitals. The redox properties of all ferrocene-containing porphyrins were investigated in a CH_2Cl_2/TFAB [TFAB = tetrabutylammonium tetrakis(perfluorophenyl)borate] system using cyclic voltammetry, differential pulse voltammetry, and square wave voltammetry methods. In all cases, oxidations of individual ferrocene substituent(s) along with porphyrin core oxidation(s) and reductions have been observed. Mixed-valence [cis-H_2Fc_2Ph_2P]^+, [trans-H_2Fc_2Ph_2P]^+, [H_2Fc_3PhP]^+, and [H_2Fc_3PhP]^(2+) complexes were formed in situ under spectroelectrochemical and chemical oxidation conditions and were characterized using UV-vis and MCD approaches. Analysis of intervalence charge-transfer bands observed in the NIR region for all mixed-valence complexes suggests electron localization and thus class II behavior in the Robin-Day classification

Optimasi Portofolio Resiko Menggunakan Model Markowitz MVO Dikaitkan dengan Keterbatasan Manusia dalam Memprediksi Masa Depan dalam Perspektif Al-Qur`an

Risk portfolio on modern finance has become increasingly technical, requiring the use of sophisticated mathematical tools in both research and practice. Since companies cannot insure themselves completely against risk, as human incompetence in predicting the future precisely that written in Al-Quran surah Luqman verse 34, they have to manage it to yield an optimal portfolio. The objective here is to minimize the variance among all portfolios, or alternatively, to maximize expected return among all portfolios that has at least a certain expected return. Furthermore, this study focuses on optimizing risk portfolio so called Markowitz MVO (Mean-Variance Optimization). Some theoretical frameworks for analysis are arithmetic mean, geometric mean, variance, covariance, linear programming, and quadratic programming. Moreover, finding a minimum variance portfolio produces a convex quadratic programming, that is minimizing the objective function ðð¥with constraintsð ð 𥠥 ðandð´ð¥ = ð. The outcome of this research is the solution of optimal risk portofolio in some investments that could be finished smoothly using MATLAB R2007b software together with its graphic analysis

Measurement of the top quark forward-backward production asymmetry and the anomalous chromoelectric and chromomagnetic moments in pp collisions at √s = 13 TeV

Abstract The parton-level top quark (t) forward-backward asymmetry and the anomalous chromoelectric (d̂ t) and chromomagnetic (μ̂ t) moments have been measured using LHC pp collisions at a center-of-mass energy of 13 TeV, collected in the CMS detector in a data sample corresponding to an integrated luminosity of 35.9 fb−1. The linearized variable AFB(1) is used to approximate the asymmetry. Candidate t t ¯ events decaying to a muon or electron and jets in final states with low and high Lorentz boosts are selected and reconstructed using a fit of the kinematic distributions of the decay products to those expected for t t ¯ final states. The values found for the parameters are AFB(1)=0.048−0.087+0.095(stat)−0.029+0.020(syst),μ̂t=−0.024−0.009+0.013(stat)−0.011+0.016(syst), and a limit is placed on the magnitude of | d̂ t| &lt; 0.03 at 95% confidence level. [Figure not available: see fulltext.

Search for new particles in events with energetic jets and large missing transverse momentum in proton-proton collisions at root s=13 TeV

A search is presented for new particles produced at the LHC in proton-proton collisions at root s = 13 TeV, using events with energetic jets and large missing transverse momentum. The analysis is based on a data sample corresponding to an integrated luminosity of 101 fb(-1), collected in 2017-2018 with the CMS detector. Machine learning techniques are used to define separate categories for events with narrow jets from initial-state radiation and events with large-radius jets consistent with a hadronic decay of a W or Z boson. A statistical combination is made with an earlier search based on a data sample of 36 fb(-1), collected in 2016. No significant excess of events is observed with respect to the standard model background expectation determined from control samples in data. The results are interpreted in terms of limits on the branching fraction of an invisible decay of the Higgs boson, as well as constraints on simplified models of dark matter, on first-generation scalar leptoquarks decaying to quarks and neutrinos, and on models with large extra dimensions. Several of the new limits, specifically for spin-1 dark matter mediators, pseudoscalar mediators, colored mediators, and leptoquarks, are the most restrictive to date.Peer reviewe

Search for heavy resonances decaying to two Higgs bosons in final states containing four b quarks

A search is presented for narrow heavy resonances X decaying into pairs of Higgs bosons (H) in proton-proton collisions collected by the CMS experiment at the LHC at root s = 8 TeV. The data correspond to an integrated luminosity of 19.7 fb(-1). The search considers HH resonances with masses between 1 and 3 TeV, having final states of two b quark pairs. Each Higgs boson is produced with large momentum, and the hadronization products of the pair of b quarks can usually be reconstructed as single large jets. The background from multijet and t (t) over bar events is significantly reduced by applying requirements related to the flavor of the jet, its mass, and its substructure. The signal would be identified as a peak on top of the dijet invariant mass spectrum of the remaining background events. No evidence is observed for such a signal. Upper limits obtained at 95 confidence level for the product of the production cross section and branching fraction sigma(gg -> X) B(X -> HH -> b (b) over barb (b) over bar) range from 10 to 1.5 fb for the mass of X from 1.15 to 2.0 TeV, significantly extending previous searches. For a warped extra dimension theory with amass scale Lambda(R) = 1 TeV, the data exclude radion scalar masses between 1.15 and 1.55 TeV

Measurement of the azimuthal anisotropy of Y(1S) and Y(2S) mesons in PbPb collisions at root s(NN)=5.02 TeV

The second-order Fourier coefficients (v(2)) characterizing the azimuthal distributions of Y(1S) and Y(2S) mesons produced in PbPb collisions at root s(NN) = 5.02 TeV are studied. The Y mesons are reconstructed in their dimuon decay channel, as measured by the CMS detector. The collected data set corresponds to an integrated luminosity of 1.7 nb(-1). The scalar product method is used to extract the v2 coefficients of the azimuthal distributions. Results are reported for the rapidity range vertical bar y vertical bar < 2.4, in the transverse momentum interval 0 < pT < 50 GeV/c, and in three centrality ranges of 10-30%, 30-50% and 50-90%. In contrast to the J/psi mesons, the measured v(2) values for the Y mesons are found to be consistent with zero. (C) 2021 The Author(s). Published by Elsevier B.V.Peer reviewe