scholarly journals On the Connections between Thermodynamics and General Relativity

2021 ◽  
Author(s):  
◽  
Jessica Santiago Silva
Keyword(s):  
General Relativity ◽  
Hawking Radiation ◽  
Rigid Motion ◽  
Irreversible Thermodynamics ◽  
Temperature Gradients ◽  
Type I ◽  
Killing Vectors ◽  
Proper Distance ◽  
Perfect Fluids ◽  
History Of

<p>In this thesis, the connections between thermodynamics and general relativity are explored. We introduce some of the history of the interaction between these two theories and take some time to individually study important concepts of both of them. Then, we move on to explore the concept of gravitationally induced temperature gradients in equilibrium states, first introduced by Richard Tolman. We explore these Tolman-like temperature gradients, understanding their physical origin and whether they can be generated by other forces or not. We then generalize this concept for fluids following generic four-velocities, which are not necessarily generated by Killing vectors, in general stationary space-times. Some examples are given.  Driven by the interest of understanding and possibly extending the concept of equilibrium for fluids following trajectories which are not generated by Killing vectors, we dedicate ourselves to a more fundamental question: can we still define thermal equilibrium for non-Killing flows? To answer this question we review two of the main theories of relativistic non-perfect fluids: Classical Irreversible Thermodynamics and Extended Irreversible Thermodynamics. We also take a tour through the interesting concept of Born-rigid motion, showing some explicit examples of non-Killing rigid flows for Bianchi Type I space-times. These results are important since they show that the Herglotz–Noether theorem cannot be extended for general curved space-times. We then connect the Born-rigid concept with the results obtained by the relativistic fluid’s equilibrium conditions and show that the exact thermodynamic equilibrium can only be achieved along a Killing flow. We do, however, introduce some interesting possibilities which are allowed for non-Killing flows.  We then launch into black hole thermodynamics, specifically studying the trans-Planckian problem for Hawking radiation. We construct a kinematical model consisting of matching two Vaidya spacetimes along a thin shell and show that, as long as the Hawking radiation is emitted only a few Planck lengths (in proper distance) away from the horizon, the trans-Plackian problem can be avoided.  We conclude with a brief discussion about what was presented and what can be done in the future.</p>

scholarly journals On the Connections between Thermodynamics and General Relativity

2021 ◽  
Author(s):  
◽  
Jessica Santiago Silva
Keyword(s):  
General Relativity ◽  
Hawking Radiation ◽  
Rigid Motion ◽  
Irreversible Thermodynamics ◽  
Temperature Gradients ◽  
Type I ◽  
Killing Vectors ◽  
Proper Distance ◽  
Perfect Fluids ◽  
History Of

<p>In this thesis, the connections between thermodynamics and general relativity are explored. We introduce some of the history of the interaction between these two theories and take some time to individually study important concepts of both of them. Then, we move on to explore the concept of gravitationally induced temperature gradients in equilibrium states, first introduced by Richard Tolman. We explore these Tolman-like temperature gradients, understanding their physical origin and whether they can be generated by other forces or not. We then generalize this concept for fluids following generic four-velocities, which are not necessarily generated by Killing vectors, in general stationary space-times. Some examples are given.  Driven by the interest of understanding and possibly extending the concept of equilibrium for fluids following trajectories which are not generated by Killing vectors, we dedicate ourselves to a more fundamental question: can we still define thermal equilibrium for non-Killing flows? To answer this question we review two of the main theories of relativistic non-perfect fluids: Classical Irreversible Thermodynamics and Extended Irreversible Thermodynamics. We also take a tour through the interesting concept of Born-rigid motion, showing some explicit examples of non-Killing rigid flows for Bianchi Type I space-times. These results are important since they show that the Herglotz–Noether theorem cannot be extended for general curved space-times. We then connect the Born-rigid concept with the results obtained by the relativistic fluid’s equilibrium conditions and show that the exact thermodynamic equilibrium can only be achieved along a Killing flow. We do, however, introduce some interesting possibilities which are allowed for non-Killing flows.  We then launch into black hole thermodynamics, specifically studying the trans-Planckian problem for Hawking radiation. We construct a kinematical model consisting of matching two Vaidya spacetimes along a thin shell and show that, as long as the Hawking radiation is emitted only a few Planck lengths (in proper distance) away from the horizon, the trans-Plackian problem can be avoided.  We conclude with a brief discussion about what was presented and what can be done in the future.</p>

CARDIOVASCULAR RISK FACTORS PECULIARITIES IN MEN UNDER 60 YEARS OLD WITH MYOCARDIAL INFARCTION AND CHRONIC INFLAMMATORY LUNG DISEASES

2020 ◽  
pp. 21-25
Author(s):  
Tupitsyn V.V. ◽  
Bataev Kh.M. ◽  
Men’shikova A.N. ◽  
Godina Z.N.
Keyword(s):  
Risk Factors ◽  
Myocardial Infarction ◽  
Heart Disease ◽  
Cardiovascular Risk ◽  
Digestive System ◽  
Control Group ◽  
Study Group ◽  
Type I ◽  
Internal Organs ◽  
History Of

Relevance. Information about the cardiovascular diseases risk factors (CVD RF) for in men with chronic lung inflam-matory pathology (CLID) is contradictory and requires clarification. Aim. To evaluate the peculiarities of CVD RF in men under 60 years of age with CLID in myocardial infarction (MI) to improve prevention. Material and methods. The study included men aged 19-60 years old with type I myocardial infarction. Patients are divided into two age-comparable groups: I - the study group, with CLID - 142 patients; II - control, without it - 424 patients. A comparative analysis of the frequency of observation of the main and additional cardiovascular risk fac-tors in groups was performed. Results. In patients of the study group, more often than in the control group we observed: hereditary burden of is-chemic heart disease (40.8 and 31.6%, respectively; p = 0.0461) and arterial hypertension (54.2 and 44.6%; p = 0.0461), frequent colds (24.6 and 12.0%; p = 0.0003), a history of extrasystoles (19.7 and 12.7%; p = 0.04); chronic foci of infections of internal organs (75.4 and 29.5%; p˂0.0001), non-ulcer lesions of the digestive system (26.1 and 14.6%; p = 0.007), smoking (95.1 and 66.3%; p˂0.0001), MI in winter (40.8 and 25.9%; p = 0.006). Less commonly were observed: oral cavity infections (9.2 and 23.6%; p˂0.0001); hypodynamia (74.5 and 82.5%; p = 0.0358), over-weight (44.4 and 55.2%; p = 0.0136), a subjective relationship between the worsening of the course of coronary heart disease and the season of the year (43.7 and 55.2%; p = 0.0173) and MI - in the autumn (14.1 and 21.9%; p = 0.006) period. Conclusions. The structure of CVD RF in men under 60 years of age with CLID with MI is characterized by the pre-dominance of smoking, non-ulcer pathology of the digestive system, frequent pro-student diseases, meteorological dependence, a history of cardiac arrhythmias and foci of internal organ infections. It is advisable to use the listed factors when planning preventive measures in such patients.

Geometry and Quantum Dynamics

2017 ◽  
Author(s):  
Laurent Baulieu ◽  
John Iliopoulos ◽  
Roland Sénéor
Keyword(s):  
General Relativity ◽  
Quantum Dynamics ◽  
Gauge Theories ◽  
Brst Symmetry ◽  
Abelian Gauge ◽  
Yang Mills ◽  
History Of ◽  
Brst Invariance

A geometrical derivation of Abelian and non- Abelian gauge theories. The Faddeev–Popov quantisation. BRST invariance and ghost fields. General discussion of BRST symmetry. Application to Yang–Mills theories and general relativity. A brief history of gauge theories.

scholarly journals Natural History of Viral Markers in Children Infected with Human T Lymphotropic Virus Type I in Jamaica

2006 ◽  
Vol 194 (5) ◽  
pp. 552-560 ◽  
Author(s):  
Elizabeth Margaret Maloney ◽  
Yoshihisa Yamano ◽  
Paul C. VanVeldhuisen ◽  
Takashi Sawada ◽  
Norma Kim ◽  
...  
Keyword(s):  
Natural History ◽  
Virus Type ◽  
Type I ◽  
T Lymphotropic Virus ◽  
History Of

Energy–momentum distributions of Ruban universe in general relativity and teleparallel gravity

2019 ◽  
Vol 34 (03n04) ◽  
pp. 1950011 ◽  
Author(s):  
C. Aktaş
Keyword(s):  
General Relativity ◽  
Bianchi Type ◽  
Teleparallel Gravity ◽  
Type I ◽  
Universe Model ◽  
Zero Energy ◽  
Bianchi Type I ◽  
Momentum Distributions ◽  
Bianchi Type I Universe

In this study, we obtain Einstein, Bergmann–Thomson (BT), Landau–Lifshitz (LL), Møller, Papapetrou (PP) and Tolman energy–momentum (EM) distributions for Ruban universe model in general relativity (GR) and teleparallel gravity (TG). We obtain same results for Einstein, Bergmann–Thomson and Landau–Lifshitz energy–momentum distributions in GR and TG. Also, we get same results for Einstein and Tolman energy–momentum distributions in GR. The Møller energy–momentum results are different in GR and TG. Also, using Ruban universe model, we obtain LRS Bianchi type I solutions and we get zero energy–momentum results for this universe model in GR and TG. These results of LRS Bianchi type I universe model agree with Aygün et al., Taşer et al., Doğru et al., Banerjee–Sen, Tryon and Xulu in different gravitation theories.

INHERITING SPACELIKE CONFORMAL KILLING VECTORS IN STRING COSMOLOGY

2003 ◽  
Vol 12 (05) ◽  
pp. 885-892 ◽  
Author(s):  
HÜSNÜ BAYSAL
Keyword(s):  
General Relativity ◽  
Cosmic Strings ◽  
String Cosmology ◽  
Conformal Killing ◽  
Killing Vectors ◽  
Conformal Killing Vectors

We study the consequences of the existence of spacelike conformal Killing vectors (SpCKV) parallel to xa for cosmic strings and string fluid in the context of general relativity. The inheritance symmetries of the cosmic strings and string fluid are discussed in the case of SpCKV. Furthermore we examine proper homothetic spacelike Killing vectors for the cosmic strings and string fluid.

The Natural History of Cerebral Dural Arteriovenous Fistulae

Neurosurgery ◽  
2012 ◽  
Vol 71 (3) ◽  
pp. 594-603 ◽  
Author(s):  
Bradley A. Gross ◽  
Rose Du
Keyword(s):  
Natural History ◽  
Significant Risk ◽  
Venous Drainage ◽  
Type I ◽  
Type Ii ◽  
Arteriovenous Fistulae ◽  
Type Iii ◽  
History Of ◽  
Venous Ectasia ◽  
Cortical Venous Drainage

Abstract BACKGROUND: Hemorrhage from cerebral dural arteriovenous fistulae (dAVF) is a considerable source of neurological morbidity and even mortality. OBJECTIVE: To evaluate the natural history of cerebral dAVF. METHODS: We reviewed our own cohort of 70 dAVF and incorporated results from the literature, synthesizing pooled hemorrhage rates and evaluating risk factors for 395 dAVF in 6 studies. RESULTS: No hemorrhages occurred during 409 lesion-years of follow-up of Borden type I dAVF; however, cortical venous drainage developed in 1.4%. Like type I dAVF, type II dAVF demonstrated a female predilection and were most commonly transverse-sigmoid or cavernous. Eighteen percent of type II dAVF presented with hemorrhage (95% confidence interval [CI]: 8%-36%), and the annual hemorrhage rate was 6% (95% CI: 0.1%-19%). Borden type III dAVF demonstrated a male predilection and were most commonly tentorial or petrosal. Thirty-four percent presented with hemorrhage (95% CI: 0.4%-49%), with an annual hemorrhage rate of 10% (95% CI: 4%-20%), increasing to 21% for those with venous ectasia (95% CI: 4%-66%). The hemorrhage rate decreased to 2% for asymptomatic or minimally symptomatic type II or III dAVF (95% CI: 0.2%-8%), and increased to 10% for those presenting with nonhemorrhagic neurological deficits (95% CI: 0.9%-41%) and to 46% for those presenting with hemorrhage (95% CI: 11%-130%). CONCLUSION: Venous ectasia is a significant risk factor for hemorrhage among dAVF with cortical venous drainage. In addition, those with hemorrhagic presentation, even compared with nonhemorrhagic neurological deficit presentation, as well as Borden type III dAVF compared with type II dAVF demonstrated a trend toward greater hemorrhage rates.

Intracranial meningioma in a patient with osteogenesis imperfecta

Open Medicine ◽  
2008 ◽  
Vol 3 (4) ◽  
pp. 517-520
Author(s):  
Parmenion Tsitsopoulos ◽  
Ioannis Anagnostopoulos ◽  
Vasileios Tsitouras ◽  
Ioannis Venizelos ◽  
Philippos Tsitsopoulos
Keyword(s):  
Osteogenesis Imperfecta ◽  
Muscle Power ◽  
Brain Mri ◽  
Intracranial Meningioma ◽  
Type I ◽  
Mri Scans ◽  
Heritable Disorder ◽  
History Of ◽  
One Year ◽  
Gait Disturbances

AbstractOsteogenesis imperfecta (OI) is a heritable disorder characterized mainly by connective tissue manifestations. In dinstinct cases, several neurological features have also been described. A 46-year-old male with a known family history of OI type I presented with progressive gait disturbances and diminished muscle strength. Brain MRI scans revealed an infiltrative intracranial mass occupying both frontoparietal lobes. The patient underwent surgical intervention. The histological diagnosis was an atypical (Grade II) meningioma. The bony parts demonstrated a mixture of osseous defects due to OI and infiltration by the tumor. At one-year follow up the patient′s muscle power partially returned while repeat MRI scans were negative for tumor recurrence.

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