1. |
- Obers, Niels A., et al.
(författare)
-
Quantum gravity phenomenology at the dawn of the multi-messenger era—A review
- 2022
-
Ingår i: Progress in Particle and Nuclear Physics. - : Elsevier BV. - 0146-6410 .- 1873-2224. ; 125
-
Forskningsöversikt (refereegranskat)abstract
- The exploration of the universe has recently entered a new era thanks to the multi-messenger paradigm, characterized by a continuous increase in the quantity and quality of experimental data that is obtained by the detection of the various cosmic messengers (photons, neutrinos, cosmic rays and gravitational waves) from numerous origins. They give us information about their sources in the universe and the properties of the intergalactic medium. Moreover, multi-messenger astronomy opens up the possibility to search for phenomenological signatures of quantum gravity. On the one hand, the most energetic events allow us to test our physical theories at energy regimes which are not directly accessible in accelerators; on the other hand, tiny effects in the propagation of very high energy particles could be amplified by cosmological distances. After decades of merely theoretical investigations, the possibility of obtaining phenomenological indications of Planck-scale effects is a revolutionary step in the quest for a quantum theory of gravity, but it requires cooperation between different communities of physicists (both theoretical and experimental). This review, prepared within the COST Action CA18108 “Quantum gravity phenomenology in the multi-messenger approach”, is aimed at promoting this cooperation by giving a state-of-the art account of the interdisciplinary expertise that is needed in the effective search of quantum gravity footprints in the production, propagation and detection of cosmic messengers.
|
|
2. |
- Koenig, Julian, et al.
(författare)
-
Cortical thickness and resting-state cardiac function across the lifespan : A cross-sectional pooled mega-analysis
- 2021
-
Ingår i: Psychophysiology. - : Wiley. - 0048-5772 .- 1469-8986 .- 1540-5958. ; 58:7
-
Tidskriftsartikel (refereegranskat)abstract
- Understanding the association between autonomic nervous system [ANS] function and brain morphology across the lifespan provides important insights into neurovisceral mechanisms underlying health and disease. Resting-state ANS activity, indexed by measures of heart rate [HR] and its variability [HRV] has been associated with brain morphology, particularly cortical thickness [CT]. While findings have been mixed regarding the anatomical distribution and direction of the associations, these inconsistencies may be due to sex and age differences in HR/HRV and CT. Previous studies have been limited by small sample sizes, which impede the assessment of sex differences and aging effects on the association between ANS function and CT. To overcome these limitations, 20 groups worldwide contributed data collected under similar protocols of CT assessment and HR/HRV recording to be pooled in a mega-analysis (N = 1,218 (50.5% female), mean age 36.7 years (range: 12–87)). Findings suggest a decline in HRV as well as CT with increasing age. CT, particularly in the orbitofrontal cortex, explained additional variance in HRV, beyond the effects of aging. This pattern of results may suggest that the decline in HRV with increasing age is related to a decline in orbitofrontal CT. These effects were independent of sex and specific to HRV; with no significant association between CT and HR. Greater CT across the adult lifespan may be vital for the maintenance of healthy cardiac regulation via the ANS—or greater cardiac vagal activity as indirectly reflected in HRV may slow brain atrophy. Findings reveal an important association between CT and cardiac parasympathetic activity with implications for healthy aging and longevity that should be studied further in longitudinal research.
|
|
3. |
- Barack, Leor, et al.
(författare)
-
Black holes, gravitational waves and fundamental physics : a roadmap
- 2019
-
Ingår i: Classical and quantum gravity. - : IOP Publishing. - 0264-9381 .- 1361-6382. ; 36:14
-
Forskningsöversikt (refereegranskat)abstract
- The grand challenges of contemporary fundamental physics dark matter, dark energy, vacuum energy, inflation and early universe cosmology, singularities and the hierarchy problem all involve gravity as a key component. And of all gravitational phenomena, black holes stand out in their elegant simplicity, while harbouring some of the most remarkable predictions of General Relativity: event horizons, singularities and ergoregions. The hitherto invisible landscape of the gravitational Universe is being unveiled before our eyes: the historical direct detection of gravitational waves by the LIGO-Virgo collaboration marks the dawn of a new era of scientific exploration. Gravitational-wave astronomy will allow us to test models of black hole formation, growth and evolution, as well as models of gravitational-wave generation and propagation. It will provide evidence for event horizons and ergoregions, test the theory of General Relativity itself, and may reveal the existence of new fundamental fields. The synthesis of these results has the potential to radically reshape our understanding of the cosmos and of the laws of Nature. The purpose of this work is to present a concise, yet comprehensive overview of the state of the art in the relevant fields of research, summarize important open problems, and lay out a roadmap for future progress. This write-up is an initiative taken within the framework of the European Action on 'Black holes, Gravitational waves and Fundamental Physics'.
|
|
4. |
- Urquia, ML, et al.
(författare)
-
Disparities in pre-eclampsia and eclampsia among immigrant women giving birth in six industrialised countries
- 2014
-
Ingår i: Obstetrics and Gynecology. - : Wiley. - 0029-7844 .- 1873-233X. ; 121:12, s. 1492-1500
-
Tidskriftsartikel (refereegranskat)abstract
- ObjectiveTo assess disparities in pre‐eclampsia and eclampsia among immigrant women from various world regions giving birth in six industrialised countries.DesignCross‐country comparative study of linked population‐based databases.SettingProvincial or regional obstetric delivery data from Australia, Canada, Spain and the USA and national data from Denmark and Sweden.PopulationAll immigrant and non‐immigrant women delivering in the six industrialised countries within the most recent 10‐year period available to each participating centre (1995–2010).MethodsData was collected using standardised definitions of the outcomes and maternal regions of birth. Pooled data were analysed with multilevel models. Within‐country analyses used stratified logistic regression to obtain odds ratios (OR ) with 95% confidence intervals (95% CI ).Main outcome measuresPre‐eclampsia, eclampsia and pre‐eclampsia with prolonged hospitalisation (cases per 1000 deliveries).ResultsThere were 9 028 802 deliveries (3 031 399 to immigrant women). Compared with immigrants from Western Europe, immigrants from Sub‐Saharan Africa and Latin America & the Caribbean were at higher risk of pre‐eclampsia (OR : 1.72; 95% CI : 1.63, 1.80 and 1.63; 95% CI : 1.57, 1.69) and eclampsia (OR : 2.12; 95% CI : 1.61, 2.79 and 1.55; 95% CI : 1.26, 1. 91), respectively, after adjustment for parity, maternal age and destination country. Compared with native‐born women, European and East Asian immigrants were at lower risk in most industrialised countries. Spain exhibited the largest disparities and Australia the smallest.ConclusionImmigrant women from Sub‐Saharan Africa and Latin America & the Caribbean require increased surveillance due to a consistently high risk of pre‐eclampsia and eclampsia.
|
|