Luciano Barosi | UFCG - Universidade Federal de Campina Grande (original) (raw)

Papers by Luciano Barosi

Research paper thumbnail of Glueballs Mass Spectrum in an Inflationary Braneworld Scenario

We address the issue of glueball masses in a holographic dual field theory on the boundary of an ... more We address the issue of glueball masses in a holographic dual field theory on the boundary of an AdS space deformed by a four-dimensional cosmological constant. These glueballs are related to scalar and tensorial fluctuations of the bulk fields on this space. In the Euclidean AdS4 case the allowed masses are discretized and are related to distinct inflaton masses on a 3-brane with several states of inflation. We then obtain the e-folds number in terms of the glueball masses. In the last part we focus on the Lorentzian dS4 case to focus on the QCD equation of state in dual field theory.

Research paper thumbnail of Holographic Description of Heavy-Quark Potentials in an Inflationary Braneworld Scenario

We study heavy-quark potential in an inflationary braneworld scenario. The scenario we consider i... more We study heavy-quark potential in an inflationary braneworld scenario. The scenario we consider is an (Euclidean) inflating braneworld AdS_4 embedded in a static Euclidean AdS_5. Using gauge/gravity duality we obtain a confining phase depending on the ratio between the Hubble parameter H in the braneworld and the brane tension σ.

Research paper thumbnail of Noncommutative field gas driven inflation

We investigate early time inflationary scenarios in an Universe filled with a dilute noncommutati... more We investigate early time inflationary scenarios in an Universe filled with a dilute noncommutative bosonic gas at high temperature. A noncommutative bosonic gas is a gas composed of bosonic scalar field with noncommutative field space on a commutative spacetime. Such noncommutative field theories was recently introduced as a generalization of quantum mechanics on a noncommutative spacetime. As key features of these theories are Lorentz invariance violation and CPT violation. In the present study we use a noncommutative bosonic field theory that besides the noncommutative parameter θ shows up a further parameter σ. This parameter σ controls the range of the noncommutativity and acts as a regulator for the theory. Both parameters play a key role in the modified dispersion relations of the noncommutative bosonic field, leading to possible striking consequences for phenomenology. In this work we obtain an equation of state p=ω(σ,θ;β)ρ for the noncommutative bosonic gas relating pressur...

Research paper thumbnail of Superstring Field Teory Action including Massless Fermions

Using Berkovits' Superstring Filed Theory action including the Ramond sector, we calculate th... more Using Berkovits' Superstring Filed Theory action including the Ramond sector, we calculate the contribution to this action coming from the tachyon and massless fermions from both GSO sectors. Some features of the action are discussed in the end, settling the ground for a more systematic treatment of spacetime fermions in superstring field theory.

Research paper thumbnail of The BINGO project. V. Further steps in component separation and bispectrum analysis

Research paper thumbnail of The BINGO project. VI. Hi halo occupation distribution and mock building

Astronomy & Astrophysics

Context. BINGO (Baryon Acoustic Oscillations from Integrated Neutral Gas Observations.) is a radi... more Context. BINGO (Baryon Acoustic Oscillations from Integrated Neutral Gas Observations.) is a radio telescope designed to survey from 980 MHz to 1260 MHz, observe the neutral hydrogen (Hi) 21 cm line, and detect the baryon acoustic oscillation signal with the intensity mapping technique. Here we present our method for generating mock maps of the 21 cm intensity mapping signal that cover the BINGO frequency range and related test results. Aims. We would like to employ N-body simulations to generate mock 21 cm intensity maps for BINGO and study the information contained in 21 cm intensity mapping observations about structure formation,Hi distribution and Hi mass-halo mass relation. Methods. We fit an Hi mass-halo mass relation from the ELUCID semianalytical galaxy catalog and applied it to the Horizen Run 4 halo catalog to generate the 21 cm mock map, which is called HOD. We also applied the abundance-matching method and matched the Horizen Run 4 galaxy catalog with the Hi mass function measured from ALFALFA, to generate the 21 cm mock map, which is called HAM Results. We studied the angular power spectrum of the mock maps and the corresponding pixel histogram. The comparison of two different mock map generation methods (HOD and HAM) is presented. We provide the fitting formula of Ω Hi , Hi bias, and the lognormal fitting parameter of the maps, which can be used to generate similar maps. We discuss the possibility of measuring Ω Hi and Hi bias by comparing the angular power spectrum of the mock maps and the theoretical calculation. We also discuss the redshift space distortion effect, the nonlinear effect, and the bin size effect in the mock map. Conclusions. By comparing the angular power spectrum measured from two different types of mock maps and the theoretical calculation, we find that the theoretical calculation can only fit the mock result at large scales. At small scales, neither the linear calculation nor the halofit nonlinear calculation can provide an accurate fitting, which reflects our poor understanding of the nonlinear distribution of Hi and its scale-dependent bias. We have found that the bias is highly sensitive to the method of populating Hi in halos, which also means that we can place constraints on the Hi distribution in halos by observing 21 cm intensity mapping. We also illustrate that only with thin frequency bins (such as 2 MHz), we can discriminate the Finger-of-God effect. All of our investigations using mocks provide useful guidance for our expectation of BINGO experiments and other 21 cm intensity mapping experiments.

Research paper thumbnail of The BINGO Project. VII. Cosmological forecasts from 21-cm intensity mapping

Astronomy & Astrophysics

Context. The 21cm line of neutral hydrogen (Hi) opens a new avenue in our exploration of the stru... more Context. The 21cm line of neutral hydrogen (Hi) opens a new avenue in our exploration of the structure and evolution of the Universe. It provides complementary data to the current large-scale structure (LSS) observations with different systematics, and thus it will be used to improve our understanding of the Lambda Cold Dark Matter (ΛCDM) model. This will ultimately constrain our cosmological models, attack unresolved tensions, and test our cosmological paradigm. Among several radio cosmological surveys designed to measure this line, BINGO is a single-dish telescope mainly designed to detect baryon acoustic oscillations (BAOs) at low redshifts (0.127 < z < 0.449). Aims. Our goal is to assess the fiducial BINGO setup and its capabilities of constraining the cosmological parameters, and to analyze the effect of different instrument configurations. Methods. We used the 21cm angular power spectra to extract cosmological information about the Hi signal and the Fisher matrix formalism to study BINGO's projected constraining power. Results. We used the Phase 1 fiducial configuration of the BINGO telescope to perform our cosmological forecasts. In addition, we investigated the impact of several instrumental setups, taking into account some instrumental systematics, and different cosmological models. Combining BINGO with Planck temperature and polarization data, the projected constraint improves from a 13% and 25% precision measurement at the 68% confidence level with Planck only to 1% and 3% for the Hubble constant and the dark energy (DE) equation of state (EoS), respectively, within the wCDM model. Assuming a Chevallier-Polarski-Linder (CPL) parameterization, the EoS parameters have standard deviations given by σ w 0 = 0.30 and σ wa = 1.2, which are improvements on the order of 30% with respect to Planck alone. We also compared BINGO's fiducial forecast with future SKA measurements and found that, although it will not provide competitive constraints on the DE EoS, significant information about Hi distribution can be acquired. We can access information about the Hi density and bias, obtaining ∼ 8.5% and ∼ 6% precision, respectively, assuming they vary with redshift at three independent bins. BINGO can also help constrain alternative models, such as interacting dark energy and modified gravity models, improving the cosmological constraints significantly. Conclusions. The fiducial BINGO configuration will be able to extract significant cosmological information from the Hi distribution and provide constraints competitive with current and future cosmological surveys. It will also help in understanding the Hi physics and systematic effects.

Research paper thumbnail of Baryon Acoustic Oscillations from Integrated Neutral Gas Observations: an instrument to observe the 21cm hydrogen line in the redshift range 0.13 < z < 0.45 - status update

Anais da Academia Brasileira de Ciencias, 2021

BINGO (BAO from Integrated Neutral Gas Observations) is a unique radio telescope designed to map ... more BINGO (BAO from Integrated Neutral Gas Observations) is a unique radio telescope designed to map the intensity of neutral hydrogen distribution at cosmological distances, making the first detection of Baryon Acoustic Oscillations (BAO) in the frequency band 980 MHz - 1260 MHz, corresponding to a redshift range 0.127 < z < 0.449. BAO is one of the most powerful probes of cosmological parameters and BINGO was designed to detect the BAO signal to a level that makes it possible to put new constraints on the equation of state of dark energy. The telescope will be built in Paraíba, Brazil and consists of two \thicksim 40m mirrors, a feedhorn array of 50 horns, and no moving parts, working as a drift-scan instrument. It will cover a 15 ^{\circ} ∘ declination strip centered at \sim \delta ∼ δ =-15 ^{\circ} ∘ , mapping \sim ∼ 5400 square degrees in the sky. The BINGO consortium is led by University of São Paulo with co-leadership at National Institute for Space Research and Campina Gra...

Research paper thumbnail of 18 2 v 1 2 0 M ay 2 00 3 1 Superstring Field Theory Action Including Massless Fermions

During the 80’s a string field theory was developed for the open bosonic string theory, following... more During the 80’s a string field theory was developed for the open bosonic string theory, following the ideas of witten for the role of noncommutativity in the string theory product (witten’s midpoint interaction) and the development of BRST techniques in string theory [1]. The natural generalization of these ideas to the case of the superstring theory didn’t achieved the success of the bosonic theory due to the divergences at the tree level for the classical action, a consequence of picture changing operators appearing explicitly in the action [2]. The interest on this kind of theories declined substantially, mainly because of the lack of any significant progress, till Sen’s conjecture on the role of tachyon in a system of unstable D-branes [3], arguing that the tachyon should have a minimum for its potential at the point where the system undergoes a decay, establishing a value for the minimum of the tachyon potential as the value of the tension of the original unstable D-brane syste...

Research paper thumbnail of The BINGO Project III: Optical design and optimisation of the focal plane

Context. The BINGO telescope was designed to measure the fluctuations of the 21-cm radiation aris... more Context. The BINGO telescope was designed to measure the fluctuations of the 21-cm radiation arising from the hyperfine transition of neutral hydrogen and aims to measure the Baryon Acoustic Oscillations (BAO) from such fluctuations, therefore serving as a pathfinder to future deeper intensity mapping surveys. The requirements for the Phase 1 of the projects consider a large reflector system (two 40 m-class dishes in a crossed-Dragone configuration), illuminating a focal plane with 28 horns to measure the sky with two circular polarisations in a drift scan mode to produce measurements of the radiation in intensity (I) as well as the circular (V) polarisation. Aims. In this paper we present the optical design for the instrument. We describe the intensity and polarisation properties of the beams and the optical arrangement of the horns in the focal plane to produce a homogeneous and well-sampled map after the end of Phase 1. Our analysis provides an optimal model for the location of t...

Research paper thumbnail of The BINGO project. I. Baryon acoustic oscillations from integrated neutral gas observations

Research paper thumbnail of The BINGO project. IV. Simulations for mission performance assessment and preliminary component separation steps

Astronomy & Astrophysics

Research paper thumbnail of Holographic description of heavy-quark potentials in an inflationary braneworld scenario

Journal of High Energy Physics, 2009

We study heavy-quark potential in an inflationary braneworld scenario. The scenario we consider i... more We study heavy-quark potential in an inflationary braneworld scenario. The scenario we consider is an (Euclidean) AdS 4 inflating braneworld embedded in a static Euclidean AdS 5. Using gauge/gravity duality we obtain a confining phase depending on the ratio between the Hubble parameter H in the braneworld and the brane tension σ.

Research paper thumbnail of GSO (−) vertex operators and open superstring field theory in hybrid variables

Journal of High Energy Physics, 2003

Research paper thumbnail of Superstring field theory action including massless fermions

Nuclear Physics B - Proceedings Supplements, 2004

Research paper thumbnail of Noncommutative field gas driven inflation

Journal of Cosmology and Astroparticle Physics, 2008

Research paper thumbnail of Glueballs Mass Spectrum in an Inflationary Braneworld Scenario

Arxiv preprint arXiv: …, 2010

Research paper thumbnail of The BINGO project. II. Instrument description

Astronomy & Astrophysics

Context. The measurement of diffuse 21-cm radiation from the hyperfine transition of neutral hydr... more Context. The measurement of diffuse 21-cm radiation from the hyperfine transition of neutral hydrogen (Hi signal) in different redshifts is an important tool for modern cosmology. However, detecting this faint signal with non-cryogenic receivers in single-dish telescopes is a challenging task. The BINGO (Baryon Acoustic Oscillations from Integrated Neutral Gas Observations) radio telescope is an instrument designed to detect baryonic acoustic oscillations (BAOs) in the cosmological Hi signal, in the redshift interval 0.127 ≤ z ≤ 0.449. Aims. This paper describes the BINGO radio telescope, including the current status of the optics, receiver, observational strategy, calibration, and the site. Methods. BINGO has been carefully designed to minimize systematics, being a transit instrument with no moving dishes and 28 horns operating in the frequency range 980 ≤ ν ≤ 1260 MHz. Comprehensive laboratory tests were conducted for many of the BINGO subsystems and the prototypes of the receiver chain, horn, polarizer, magic tees, and transitions have been successfully tested between 2018-2020. The survey was designed to cover ∼ 13% of the sky, with the primary mirror pointing at declination δ = −15 •. The telescope will see an instantaneous declination strip of 14.75 •. Results. The results of the prototype tests closely meet those obtained during the modeling process, suggesting BINGO will perform according to our expectations. After one year of observations with a 60% duty cycle and 28 horns, BINGO should achieve an expected sensitivity of 102 µK per 9.33 MHz frequency channel, one polarization, and be able to measure the Hi power spectrum in a competitive time frame.

Research paper thumbnail of Glueballs Mass Spectrum in an Inflationary Braneworld Scenario

We address the issue of glueball masses in a holographic dual field theory on the boundary of an ... more We address the issue of glueball masses in a holographic dual field theory on the boundary of an AdS space deformed by a four-dimensional cosmological constant. These glueballs are related to scalar and tensorial fluctuations of the bulk fields on this space. In the Euclidean AdS4 case the allowed masses are discretized and are related to distinct inflaton masses on a 3-brane with several states of inflation. We then obtain the e-folds number in terms of the glueball masses. In the last part we focus on the Lorentzian dS4 case to focus on the QCD equation of state in dual field theory.

Research paper thumbnail of Holographic Description of Heavy-Quark Potentials in an Inflationary Braneworld Scenario

We study heavy-quark potential in an inflationary braneworld scenario. The scenario we consider i... more We study heavy-quark potential in an inflationary braneworld scenario. The scenario we consider is an (Euclidean) inflating braneworld AdS_4 embedded in a static Euclidean AdS_5. Using gauge/gravity duality we obtain a confining phase depending on the ratio between the Hubble parameter H in the braneworld and the brane tension σ.

Research paper thumbnail of Noncommutative field gas driven inflation

We investigate early time inflationary scenarios in an Universe filled with a dilute noncommutati... more We investigate early time inflationary scenarios in an Universe filled with a dilute noncommutative bosonic gas at high temperature. A noncommutative bosonic gas is a gas composed of bosonic scalar field with noncommutative field space on a commutative spacetime. Such noncommutative field theories was recently introduced as a generalization of quantum mechanics on a noncommutative spacetime. As key features of these theories are Lorentz invariance violation and CPT violation. In the present study we use a noncommutative bosonic field theory that besides the noncommutative parameter θ shows up a further parameter σ. This parameter σ controls the range of the noncommutativity and acts as a regulator for the theory. Both parameters play a key role in the modified dispersion relations of the noncommutative bosonic field, leading to possible striking consequences for phenomenology. In this work we obtain an equation of state p=ω(σ,θ;β)ρ for the noncommutative bosonic gas relating pressur...

Research paper thumbnail of Superstring Field Teory Action including Massless Fermions

Using Berkovits' Superstring Filed Theory action including the Ramond sector, we calculate th... more Using Berkovits' Superstring Filed Theory action including the Ramond sector, we calculate the contribution to this action coming from the tachyon and massless fermions from both GSO sectors. Some features of the action are discussed in the end, settling the ground for a more systematic treatment of spacetime fermions in superstring field theory.

Research paper thumbnail of The BINGO project. V. Further steps in component separation and bispectrum analysis

Research paper thumbnail of The BINGO project. VI. Hi halo occupation distribution and mock building

Astronomy & Astrophysics

Context. BINGO (Baryon Acoustic Oscillations from Integrated Neutral Gas Observations.) is a radi... more Context. BINGO (Baryon Acoustic Oscillations from Integrated Neutral Gas Observations.) is a radio telescope designed to survey from 980 MHz to 1260 MHz, observe the neutral hydrogen (Hi) 21 cm line, and detect the baryon acoustic oscillation signal with the intensity mapping technique. Here we present our method for generating mock maps of the 21 cm intensity mapping signal that cover the BINGO frequency range and related test results. Aims. We would like to employ N-body simulations to generate mock 21 cm intensity maps for BINGO and study the information contained in 21 cm intensity mapping observations about structure formation,Hi distribution and Hi mass-halo mass relation. Methods. We fit an Hi mass-halo mass relation from the ELUCID semianalytical galaxy catalog and applied it to the Horizen Run 4 halo catalog to generate the 21 cm mock map, which is called HOD. We also applied the abundance-matching method and matched the Horizen Run 4 galaxy catalog with the Hi mass function measured from ALFALFA, to generate the 21 cm mock map, which is called HAM Results. We studied the angular power spectrum of the mock maps and the corresponding pixel histogram. The comparison of two different mock map generation methods (HOD and HAM) is presented. We provide the fitting formula of Ω Hi , Hi bias, and the lognormal fitting parameter of the maps, which can be used to generate similar maps. We discuss the possibility of measuring Ω Hi and Hi bias by comparing the angular power spectrum of the mock maps and the theoretical calculation. We also discuss the redshift space distortion effect, the nonlinear effect, and the bin size effect in the mock map. Conclusions. By comparing the angular power spectrum measured from two different types of mock maps and the theoretical calculation, we find that the theoretical calculation can only fit the mock result at large scales. At small scales, neither the linear calculation nor the halofit nonlinear calculation can provide an accurate fitting, which reflects our poor understanding of the nonlinear distribution of Hi and its scale-dependent bias. We have found that the bias is highly sensitive to the method of populating Hi in halos, which also means that we can place constraints on the Hi distribution in halos by observing 21 cm intensity mapping. We also illustrate that only with thin frequency bins (such as 2 MHz), we can discriminate the Finger-of-God effect. All of our investigations using mocks provide useful guidance for our expectation of BINGO experiments and other 21 cm intensity mapping experiments.

Research paper thumbnail of The BINGO Project. VII. Cosmological forecasts from 21-cm intensity mapping

Astronomy & Astrophysics

Context. The 21cm line of neutral hydrogen (Hi) opens a new avenue in our exploration of the stru... more Context. The 21cm line of neutral hydrogen (Hi) opens a new avenue in our exploration of the structure and evolution of the Universe. It provides complementary data to the current large-scale structure (LSS) observations with different systematics, and thus it will be used to improve our understanding of the Lambda Cold Dark Matter (ΛCDM) model. This will ultimately constrain our cosmological models, attack unresolved tensions, and test our cosmological paradigm. Among several radio cosmological surveys designed to measure this line, BINGO is a single-dish telescope mainly designed to detect baryon acoustic oscillations (BAOs) at low redshifts (0.127 < z < 0.449). Aims. Our goal is to assess the fiducial BINGO setup and its capabilities of constraining the cosmological parameters, and to analyze the effect of different instrument configurations. Methods. We used the 21cm angular power spectra to extract cosmological information about the Hi signal and the Fisher matrix formalism to study BINGO's projected constraining power. Results. We used the Phase 1 fiducial configuration of the BINGO telescope to perform our cosmological forecasts. In addition, we investigated the impact of several instrumental setups, taking into account some instrumental systematics, and different cosmological models. Combining BINGO with Planck temperature and polarization data, the projected constraint improves from a 13% and 25% precision measurement at the 68% confidence level with Planck only to 1% and 3% for the Hubble constant and the dark energy (DE) equation of state (EoS), respectively, within the wCDM model. Assuming a Chevallier-Polarski-Linder (CPL) parameterization, the EoS parameters have standard deviations given by σ w 0 = 0.30 and σ wa = 1.2, which are improvements on the order of 30% with respect to Planck alone. We also compared BINGO's fiducial forecast with future SKA measurements and found that, although it will not provide competitive constraints on the DE EoS, significant information about Hi distribution can be acquired. We can access information about the Hi density and bias, obtaining ∼ 8.5% and ∼ 6% precision, respectively, assuming they vary with redshift at three independent bins. BINGO can also help constrain alternative models, such as interacting dark energy and modified gravity models, improving the cosmological constraints significantly. Conclusions. The fiducial BINGO configuration will be able to extract significant cosmological information from the Hi distribution and provide constraints competitive with current and future cosmological surveys. It will also help in understanding the Hi physics and systematic effects.

Research paper thumbnail of Baryon Acoustic Oscillations from Integrated Neutral Gas Observations: an instrument to observe the 21cm hydrogen line in the redshift range 0.13 < z < 0.45 - status update

Anais da Academia Brasileira de Ciencias, 2021

BINGO (BAO from Integrated Neutral Gas Observations) is a unique radio telescope designed to map ... more BINGO (BAO from Integrated Neutral Gas Observations) is a unique radio telescope designed to map the intensity of neutral hydrogen distribution at cosmological distances, making the first detection of Baryon Acoustic Oscillations (BAO) in the frequency band 980 MHz - 1260 MHz, corresponding to a redshift range 0.127 < z < 0.449. BAO is one of the most powerful probes of cosmological parameters and BINGO was designed to detect the BAO signal to a level that makes it possible to put new constraints on the equation of state of dark energy. The telescope will be built in Paraíba, Brazil and consists of two \thicksim 40m mirrors, a feedhorn array of 50 horns, and no moving parts, working as a drift-scan instrument. It will cover a 15 ^{\circ} ∘ declination strip centered at \sim \delta ∼ δ =-15 ^{\circ} ∘ , mapping \sim ∼ 5400 square degrees in the sky. The BINGO consortium is led by University of São Paulo with co-leadership at National Institute for Space Research and Campina Gra...

Research paper thumbnail of 18 2 v 1 2 0 M ay 2 00 3 1 Superstring Field Theory Action Including Massless Fermions

During the 80’s a string field theory was developed for the open bosonic string theory, following... more During the 80’s a string field theory was developed for the open bosonic string theory, following the ideas of witten for the role of noncommutativity in the string theory product (witten’s midpoint interaction) and the development of BRST techniques in string theory [1]. The natural generalization of these ideas to the case of the superstring theory didn’t achieved the success of the bosonic theory due to the divergences at the tree level for the classical action, a consequence of picture changing operators appearing explicitly in the action [2]. The interest on this kind of theories declined substantially, mainly because of the lack of any significant progress, till Sen’s conjecture on the role of tachyon in a system of unstable D-branes [3], arguing that the tachyon should have a minimum for its potential at the point where the system undergoes a decay, establishing a value for the minimum of the tachyon potential as the value of the tension of the original unstable D-brane syste...

Research paper thumbnail of The BINGO Project III: Optical design and optimisation of the focal plane

Context. The BINGO telescope was designed to measure the fluctuations of the 21-cm radiation aris... more Context. The BINGO telescope was designed to measure the fluctuations of the 21-cm radiation arising from the hyperfine transition of neutral hydrogen and aims to measure the Baryon Acoustic Oscillations (BAO) from such fluctuations, therefore serving as a pathfinder to future deeper intensity mapping surveys. The requirements for the Phase 1 of the projects consider a large reflector system (two 40 m-class dishes in a crossed-Dragone configuration), illuminating a focal plane with 28 horns to measure the sky with two circular polarisations in a drift scan mode to produce measurements of the radiation in intensity (I) as well as the circular (V) polarisation. Aims. In this paper we present the optical design for the instrument. We describe the intensity and polarisation properties of the beams and the optical arrangement of the horns in the focal plane to produce a homogeneous and well-sampled map after the end of Phase 1. Our analysis provides an optimal model for the location of t...

Research paper thumbnail of The BINGO project. I. Baryon acoustic oscillations from integrated neutral gas observations

Research paper thumbnail of The BINGO project. IV. Simulations for mission performance assessment and preliminary component separation steps

Astronomy & Astrophysics

Research paper thumbnail of Holographic description of heavy-quark potentials in an inflationary braneworld scenario

Journal of High Energy Physics, 2009

We study heavy-quark potential in an inflationary braneworld scenario. The scenario we consider i... more We study heavy-quark potential in an inflationary braneworld scenario. The scenario we consider is an (Euclidean) AdS 4 inflating braneworld embedded in a static Euclidean AdS 5. Using gauge/gravity duality we obtain a confining phase depending on the ratio between the Hubble parameter H in the braneworld and the brane tension σ.

Research paper thumbnail of GSO (−) vertex operators and open superstring field theory in hybrid variables

Journal of High Energy Physics, 2003

Research paper thumbnail of Superstring field theory action including massless fermions

Nuclear Physics B - Proceedings Supplements, 2004

Research paper thumbnail of Noncommutative field gas driven inflation

Journal of Cosmology and Astroparticle Physics, 2008

Research paper thumbnail of Glueballs Mass Spectrum in an Inflationary Braneworld Scenario

Arxiv preprint arXiv: …, 2010

Research paper thumbnail of The BINGO project. II. Instrument description

Astronomy & Astrophysics

Context. The measurement of diffuse 21-cm radiation from the hyperfine transition of neutral hydr... more Context. The measurement of diffuse 21-cm radiation from the hyperfine transition of neutral hydrogen (Hi signal) in different redshifts is an important tool for modern cosmology. However, detecting this faint signal with non-cryogenic receivers in single-dish telescopes is a challenging task. The BINGO (Baryon Acoustic Oscillations from Integrated Neutral Gas Observations) radio telescope is an instrument designed to detect baryonic acoustic oscillations (BAOs) in the cosmological Hi signal, in the redshift interval 0.127 ≤ z ≤ 0.449. Aims. This paper describes the BINGO radio telescope, including the current status of the optics, receiver, observational strategy, calibration, and the site. Methods. BINGO has been carefully designed to minimize systematics, being a transit instrument with no moving dishes and 28 horns operating in the frequency range 980 ≤ ν ≤ 1260 MHz. Comprehensive laboratory tests were conducted for many of the BINGO subsystems and the prototypes of the receiver chain, horn, polarizer, magic tees, and transitions have been successfully tested between 2018-2020. The survey was designed to cover ∼ 13% of the sky, with the primary mirror pointing at declination δ = −15 •. The telescope will see an instantaneous declination strip of 14.75 •. Results. The results of the prototype tests closely meet those obtained during the modeling process, suggesting BINGO will perform according to our expectations. After one year of observations with a 60% duty cycle and 28 horns, BINGO should achieve an expected sensitivity of 102 µK per 9.33 MHz frequency channel, one polarization, and be able to measure the Hi power spectrum in a competitive time frame.