| Records |
Author  |
Reig, M. |
| Title |
The stochastic axiverse |
Type |
Journal Article |
| Year |
2021 |
Publication |
Journal of High Energy Physics |
Abbreviated Journal |
J. High Energy Phys. |
| Volume |
09 |
Issue |
9 |
Pages |
207 - 40pp |
| Keywords |
Cosmology of Theories beyond the SM; Beyond Standard Model; Compactification and String Models |
| Abstract |
In addition to spectacular signatures such as black hole superradiance and the rotation of CMB polarization, the plenitude of axions appearing in the string axiverse may have potentially dangerous implications. An example is the cosmological overproduction of relic axions and moduli by the misalignment mechanism, more pronounced in regions where the signals mentioned above may be observable, that is for large axion decay constant. In this work, we study the minimal requirements to soften this problem and show that the fundamental requirement is a long period of low-scale inflation. However, in this case, if the inflationary Hubble scale is lower than around O(100) eV, no relic DM axion is produced in the early Universe. Cosmological production of some axions may be activated, via the misalignment mechanism, if their potential minimum changes between inflation and today. As a particular example, we study in detail how the maximal-misalignment mechanism dilutes the effect of dangerous axions and allows the production of axion DM in a controlled way. In this case, the potential of the axion that realises the mechanism shifts by a factor increment theta = pi between the inflationary epoch and today, and the axion starts to oscillate from the top of its potential. We also show that axions with masses m(a) similar to O(1 – 100) H-0 realising the maximal-misalignment mechanism generically behave as dark energy with a decay constant that can take values well below the Planck scale, avoiding problems associated to super-Planckian scales. Finally, we briefly study the basic phenomenological implications of the mechanism and comment on the compatibility of this type of maximally-misaligned quintessence with the swampland criteria. |
| Address |
[Reig, Mario] Univ Valencia, CSIC, Inst Fis Corpuscular, C Catedratico Jose Beltran 2, E-46980 Paterna, Valencia, Spain, Email: mario.reig@ifis.uv.es |
| Corporate Author |
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Thesis |
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| Publisher |
Springer |
Place of Publication |
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Editor |
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| Language |
English |
Summary Language |
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Original Title |
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Series Title |
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Series Issue |
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Edition |
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| ISSN |
1029-8479 |
ISBN |
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Medium |
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| Area |
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Expedition |
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Conference |
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| Notes |
WOS:000702371800004 |
Approved |
no |
| Is ISI |
yes |
International Collaboration |
no |
| Call Number |
IFIC @ pastor @ |
Serial |
4977 |
| Permanent link to this record |
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| Author |
Real, D.; Sanchez Losa, A.; Diaz, A.; Salesa Greus, F.; Calvo, D. |
| Title |
The Neutrino Mediterranean Observatory Laser Beacon: Design and Qualification |
Type |
Journal Article |
| Year |
2023 |
Publication |
Applied Sciences-Basel |
Abbreviated Journal |
Appl. Sci.-Basel |
| Volume |
13 |
Issue |
17 |
Pages |
9935 - 16pp |
| Keywords |
neutrino telescope; time calibration; laser beacon |
| Abstract |
This paper encapsulates details of the NEMO laser beacon's design, offering a profound contribution to the field of the time calibration of underwater neutrino telescopes. The mechanical design of the laser beacon, which operates at a depth of 3500 m, is presented, together with the design of the antibiofouling system employed to endure the operational pressure and optimize the operational range, enhancing its functionality and enabling time calibration among multiple towers. A noteworthy innovation central to this development lies in the battery system. This configuration enhances the device's portability, a crucial aspect in underwater operations. The comprehensive design of the laser beacon, encompassing the container housing, the requisite battery system for operation, electronics, and an effective antibiofouling system, is described in this paper. Additionally, this paper presents the findings of the laser beacon's qualification process. |
| Address |
[Real, Diego; Losa, Agustin Sanchez; Greus, Francisco Salesa; Calvo, David] CSIC Univ Valencia, IFIC Inst Fis Corpuscular, C Catedrat Jose Beltran 2, Paterna 46980, Spain, Email: real@ific.uv.es; |
| Corporate Author |
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Thesis |
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| Publisher |
Mdpi |
Place of Publication |
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Editor |
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| Language |
English |
Summary Language |
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Original Title |
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ISBN |
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Medium |
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| Area |
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Expedition |
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Conference |
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| Notes |
WOS:001063704500001 |
Approved |
no |
| Is ISI |
yes |
International Collaboration |
no |
| Call Number |
IFIC @ pastor @ |
Serial |
5668 |
| Permanent link to this record |
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| Author |
Real, D.; Calvo, D.; Zornoza, J.D.; Manzaneda, M.; Gozzini, R.; Ricolfe-Viala, C.; Lajara, R.; Albiol, F. |
| Title |
Fast Coincidence Filter for Silicon Photomultiplier Dark Count Rate Rejection |
Type |
Journal Article |
| Year |
2024 |
Publication |
Sensors |
Abbreviated Journal |
Sensors |
| Volume |
24 |
Issue |
7 |
Pages |
2084 - 12pp |
| Keywords |
time-to-digital converters; neutrino telescopes; silicon photomultipliers; dark noise rate filtering |
| Abstract |
Silicon Photomultipliers find applications across various fields. One potential Silicon Photomultiplier application domain is neutrino telescopes, where they may enhance the angular resolution. However, the elevated dark count rate associated with Silicon Photomultipliers represents a significant challenge to their widespread utilization. To address this issue, it is proposed to use Silicon Photomultipliers and Photomultiplier Tubes together. The Photomultiplier Tube signals serve as a trigger to mitigate the dark count rate, thereby preventing undue saturation of the available bandwidth. This paper presents an investigation into a fast and resource-efficient method for filtering the Silicon Photomultiplier dark count rate. A low-resource and fast coincident filter has been developed, which removes the Silicon Photomultiplier dark count rate by using as a trigger the Photomultiplier Tube input signals. The architecture of the coincidence filter, together with the first results obtained, which validate the effectiveness of this method, is presented. |
| Address |
[Real, Diego; Calvo, David; Zornoza, Juan de Dios; Manzaneda, Mario; Gozzini, Rebecca; Albiol, Francisco] CSIC Univ Valencia, IFIC Inst Fis Corpuscular, C Catedrat Jose Beltran 2, Paterna 46980, Spain, Email: real@ific.uv.es; |
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Thesis |
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| Publisher |
Mdpi |
Place of Publication |
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Editor |
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| Language |
English |
Summary Language |
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Original Title |
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Series Title |
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Abbreviated Series Title |
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Series Issue |
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Edition |
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ISBN |
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Medium |
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| Area |
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Expedition |
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Conference |
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| Notes |
WOS:001201226600001 |
Approved |
no |
| Is ISI |
yes |
International Collaboration |
no |
| Call Number |
IFIC @ pastor @ |
Serial |
6063 |
| Permanent link to this record |
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| Author |
Real, D.; Calvo, D.; Zornoza, J.D.; Manzaneda, M. |
| Title |
White Rabbit Expansion Board: Design, Architecture, and Signal Integrity Simulations |
Type |
Journal Article |
| Year |
2023 |
Publication |
Electronics |
Abbreviated Journal |
Electronics |
| Volume |
12 |
Issue |
16 |
Pages |
3394 - 16pp |
| Keywords |
subnanosecond synchronization; White Rabbit; IEEE Std 1588-2019; virtual prototyping |
| Abstract |
The White Rabbit protocol allows synchronization and communication via an optical link in an integrated, modular, and scalable manner. It provides a solution to those applications that have very demanding requirements in terms of synchronization. Field-programmable gate arrays are used to implement the protocol; additionally, special hardware is needed to provide the necessary clock signals used by the dual-mixer time difference for precise phase measurement. In the present work, an expansion board that allows for White Rabbit functionality is presented. The expansion board contains the oscillators required by the White Rabbit protocol, one running at 125 MHz and another at 124.922 MHZ. The architecture of this board includes two oscillator systems for tests and comparison. One is based on VCOs and another on crystal oscillators running at the desired frequencies. In addition, it incorporates a temperature sensor, from where the medium access control address is extracted, an electrically erasable programmable read-only memory, a pulse-per-second output, and a USB UART to access the White Rabbit IP core at the field-programmable gate array. Finally, to ensure the quality of the layout design and guarantee the level of synchronization desired, the results of the power and signal integrity simulations are also presented. |
| Address |
[Real, Diego; Calvo, David; de Dios Zornoza, Juan; Manzaneda, Mario] Univ Valencia, IFIC Inst Fis Corpuscular, CSIC, C Catedrat Jose Beltran 2, Paterna 46980, Spain, Email: real@ific.uv.es; |
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Thesis |
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| Publisher |
Mdpi |
Place of Publication |
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Editor |
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| Language |
English |
Summary Language |
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Original Title |
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Series Title |
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Abbreviated Series Title |
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Series Issue |
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Edition |
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ISBN |
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Medium |
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| Area |
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Expedition |
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Conference |
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| Notes |
WOS:001056236300001 |
Approved |
no |
| Is ISI |
yes |
International Collaboration |
no |
| Call Number |
IFIC @ pastor @ |
Serial |
5628 |
| Permanent link to this record |
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| Author |
Real, D.; Calvo, D.; Diaz, A.; Salesa Greus, F.; Sanchez Losa, A. |
| Title |
A Narrow Optical Pulse Emitter Based on LED: NOPELED |
Type |
Journal Article |
| Year |
2022 |
Publication |
Sensors |
Abbreviated Journal |
Sensors |
| Volume |
22 |
Issue |
19 |
Pages |
7683 - 15pp |
| Keywords |
short optical pulse; optical instrumentation |
| Abstract |
Light sources emitting short pulses are needed in many particle physics experiments using optical sensors as they can replicate the light produced by the particles being detected and are also an important calibration and test element. This work presents NOPELED, a light source based on LEDs emitting short optical pulses with typical rise times of less than 3 ns and Full Width at Half Maximum lower than 7 ns. The emission wavelength depends on the model of LED used. Several LED models have been characterized in the range from 405 to 532 nm, although NOPELED can work with LED emitting wavelengths outside of that region. While the wavelength is fixed for a given LED model, the intensity and the frequency of the optical pulse can be controlled. NOPELED, which also has low cost and simple operation, can be operated remotely, making it appropriate for either different physics experiments needing in-place light sources such as astrophysical neutrino detectors using photo-multipliers or positron emission tomography devices using scintillation counters, or, beyond physics, applications needing short pulses of light such as protein fluorescence or chemodetection of heavy metals. |
| Address |
[Real, Diego; Calvo, David; Salesa Greus, Francisco; Sanchez Losa, Agustin] Univ Valencia, IFIC Inst Fis Corpuscular, CSIC, C Catedrat Jose Beltran 2, Paterna 46980, Spain, Email: real@ific.uv.es; |
| Corporate Author |
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Thesis |
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| Publisher |
Mdpi |
Place of Publication |
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Editor |
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| Language |
English |
Summary Language |
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Original Title |
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Series Title |
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Abbreviated Series Title |
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Series Issue |
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Edition |
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ISBN |
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Medium |
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| Area |
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Expedition |
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Conference |
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| Notes |
WOS:000867935300001 |
Approved |
no |
| Is ISI |
yes |
International Collaboration |
no |
| Call Number |
IFIC @ pastor @ |
Serial |
5381 |
| Permanent link to this record |
