155 research outputs found
Modeling Cosmological Perturbations of Thermal Inflation
We consider a simple system consisting of matter, radiation and vacuum
components to model the impact of thermal inflation on the evolution of
primordial perturbations. The vacuum energy magnifies the modes entering the
horizon before its domination, making them potentially observable, and the
resulting transfer function reflects the phase changes and energy contents. To
determine the transfer function, we follow the curvature perturbation from well
outside the horizon during radiation domination to well outside the horizon
during vacuum domination and evaluate it on a constant radiation density
hypersurface, as is appropriate for the case of thermal inflation. The shape of
the transfer function is determined by the ratio of vacuum energy to radiation
at matter-radiation equality, which we denote by , and has two
characteristic scales, and , corresponding to the
horizon sizes at matter radiation equality and the beginning of the inflation,
respectively. If , the universe experiences radiation, matter
and vacuum domination eras and the transfer function is flat for , oscillates with amplitude for and
oscillates with amplitude for . For , the
matter domination era disappears, and the transfer function reduces to being
flat for and oscillating with amplitude for .Comment: 17 pages, 5 figures, submitted to JCA
Demonstration of the Hayden-Preskill protocol via mutual information
We construct the Hayden-Preskill protocol by using a system of spin-1/2
particles and demonstrate information flows of this system which can mimic
black holes. We first define an analogous black hole as a collection of
such particles. Second, we take the particles from inside to outside the black
hole to define an analogous system of Hawking radiation as outside
particles. When the black hole and the radiation have the maximum entanglement
at the Page time, we take an entangled pair system and . The particles
of fall into the black hole while their counterparts of remain outside.
If we assume rapid mixing of the particle states in the black hole ,
can the information of rapidly escape from the black hole like a mirror? We
numerically show that if we turn on the rapid mixing in the black hole, the
original information of rapidly escapes from the black hole to outside in
the form of the mutual information between and . On the other hand, if
the mixing between and is not enough, the information escapes slowly.
Hence, we explicitly demonstrate the original conjecture of Hayden and
Preskill. We emphasize that enough mixing is an essential condition to make the
Hayden-Preskill protocol functionally work.Comment: 12 pages, 4 figure
Before the Page time: maximum entanglements or the return of the monster?
The entropy of Hawking radiation is approximately equal to the maximum of
entanglement entropy if a black hole is in a state before the Page time, i.e.,
when the entropy of Hawking radiation is smaller than the entropy of the black
hole. However, if there exists a process generating smaller entanglements
rather than maximal entanglements, the entropy of Hawking radiation will become
smaller than the maximum of the entanglement entropy before the Page time. If
this process accumulates, even though the probability is small, the emitted
radiation can eventually be distinguished from the exactly thermal state. In
this paper, we provide several interpretations of this phenomenon: (1)
information of the collapsed matter is emitted before the Page time, (2) there
exists a firewall or a non-local effect before the Page time, or (3) the
statistical entropy is greater than the areal entropy; a monster is formed. Our
conclusion will help resolve the information loss paradox by providing
groundwork for further research.Comment: 19 pages, 8 figure
Concomitant renal insufficiency and diabetes mellitus as prognostic factors for acute myocardial infarction
<p>Abstract</p> <p>Background</p> <p>Diabetes mellitus and renal dysfunction are prognostic factors after acute myocardial infarction (AMI). However, few studies have assessed the effects of renal insufficiency in association with diabetes in the context of AMI. Here, we investigated the clinical outcomes according to the concomitance of renal dysfunction and diabetes mellitus in patients with AMI.</p> <p>Methods</p> <p>From November 2005 to August 2008, 9905 patients (63 ± 13 years; 70% men) with AMI were enrolled in a nationwide prospective Korea Acute Myocardial Infarction Registry (KAMIR) and were categorized into 4 groups: Group I (n = 5700) had neither diabetes nor renal insufficiency (glomerular filtration rate [GFR] ≥ 60 ml/min/1.73 m<sup>2</sup>), Group II (n = 1730) had diabetes but no renal insufficiency, Group III (n = 1431) had no diabetes but renal insufficiency, and Group IV (n = 1044) had both diabetes and renal insufficiency. The primary endpoints were major adverse cardiac events (MACE), including a composite of all cause-of-death, myocardial infarction, target lesion revascularization, and coronary artery bypass graft after 1-year clinical follow-up.</p> <p>Results</p> <p>Primary endpoints occurred in 1804 (18.2%) patients. There were significant differences in composite MACE among the 4 groups (Group I, 12.5%; Group II, 15.7%; Group III, 30.5%; Group IV, 36.5%; <it>p </it>< 0.001). In a Cox proportional hazards model, after adjusting for multiple covariates, the 1-year mortality increased stepwise from Group III to IV as compared with Group I (hazard ratio [HR], 1.96; 95% confidence interval [CI], 1.34-2.86; <it>p </it>= 0.001; and HR, 2.42; 95% CI, 1.62-3.62; <it>p </it>< 0.001, respectively). However, Kaplan-Meier analysis showed no significant difference in probability of death at 1 year between Group III and IV (p = 0.288).</p> <p>Conclusions</p> <p>Renal insufficiency, especially in association with diabetes, is associated with the occurrence of composite MACE and indicates poor prognosis in patients with AMI. Categorization of patients with diabetes and/or renal insufficiency provides valuable information for early-risk stratification of AMI patients.</p
Assessment of the conventional radial artery with optical coherent tomography after the snuffbox approach
Background: This study aimed to evaluate acute injuries of the radial artery (RA) using optical coherence tomography (OCT) in patients who underwent coronary intervention via the snuffbox approach.
Methods: Forty-six patients, who underwent coronary intervention and assessment of the conventional RA using OCT via the snuffbox approach, were enrolled from two university hospitals between August 2018 and August 2019.
Results: The mean age of the patients was 65.1 years. In this study population, 6-French (Fr) sheaths were used. The mean diameter of the conventional RA was 2.89 ± 0.33 mm, and the mean lumen area of the conventional RA was 6.68 ± 1.56 mm2. Acute injuries of the conventional RA, after the snuffbox approach, were observed in 5 (10.9%) patients. Intimal tear was observed in the RA in 1 (2.2%) case. Intraluminal thrombi, without vessel injuries, were detected in the RA in 4 (8.7%) cases. However, medial dissection was not observed in the OCT analysis.
Conclusions: This retrospective OCT-based study showed that the diameter of the conventional RA was 2.89 mm and acute vessel injury of the conventional RA was rare in patients who underwent coronary intervention via the snuffbox approach
TCTAP A-013 Prognostic Impact of Bundle Branch Block in Diabetic Patients with Acute Myocardial Infarction
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