On the gauge fixing in the Hamiltonian analysis of general teleparallel theories

The covariant formulation of teleparallel gravity theories must include the spin connection, which has 6 degrees of freedom. One can, however, always choose a gauge such that the spin connection is put to zero. In principle this gauge may affect counting of degrees of freedom in the Hamiltonian analysis. We show for general teleparallel theories of gravity, that fixing the gauge such that the spin connection vanishes in fact does not affect the counting of degrees of freedom. This manifests in the fact that the momenta of the Lorentz transformations which generate the spin connection are fully determined by the momenta of the tetrads.Comment: 8 pages, no figures, Contribution to the proceedings of the conference "Teleparallel Universes" in Salamanc

Problematic Men and Restricted Women: A Discourse Analysis on Swedish Feminism

Feminism is everywhere: in all sorts of media, in fashion, in entertainment, and in politics. By focusing on social media, this thesis examines how self-identified feminists construct feminism in Sweden. The construction is found in a popular Swedish feminist podcast, a debate on the premises of sisterhood, a women’s separatist Facebook group, and an interview with the second wave feminist Agnes Wold. Drawing on Laclau and Mouffe’s discourse theory and Carol Bacchi’s policy analysis, What’s the Problem Represented to be, this thesis examines how the hegemonic feminism is constructed across the identified discourses. These discourses, one of problematic men and one of restricted women, exist in relation to each other and contain the notion that men are a problem that affects women’s living conditions. With regard to what it excludes, the hegemonic feminism is heteronormative and constructed from the perspectives of the self-identified feminists. The discourse analysis also shows that the feminists protect and care for other women solely because they are women

Kovariantsete teleparalleelsete gravitatsiooniteooriate Hamiltoni analüüs

Möödunud sajandil valitses maailmapilt et gravitatsiooni kirjeldab jõuteooria asemel Üldrelatiivsusteooria, mille raames mateeria mõjub aegruumi geomeetriat milles me elame. Eelmainitud kirjeldus on tõestanud oma sobivust paljudes eksperimentaalsetes ja vaatuslikes testides alates Albert Einsteini gravitatsiooniteooria püstitamisest. Lisaks on ta oma edukust näidanud kosmoloogilise standardmudeli lahendamatu osana. Sellest hoolimata on kaasaegsed vaatlused avaldanud statistiliselt märkamisväärseid pingeid kosmoloogilises standardmudelis. Lisaks koosneb 95% universumi mateeriasisust seni selgitamatuks jäänud tumeainest ja tumeenergiast. Nende probleemide käsitlemiseks on võimalik uurida modifitseeritud gravitatsiooniteooriaid. Selles väitekirjas on uuritud modifitseeritud teleparalleelsed gravitatsiooniteooriad. Need teooriad lähtuvad arusaamast et Üldrelatiivsusteooriat on võimalik kirjeldada füüsikaliiselt ekvivalentsel viisil. Siiski näitab teleparalleelne kirjeldus ette uusi võimalusi gravitatsiooniteooria modifitseerida. Väitekirjas on lähemalt uuritud f (TNGR ) gravitatsiooniteooria ja käsitletud küsimus kas f (TNGR ) on teoreetilise vaatenurga alt kooskõlaline gravitatsiooniteooria. Selle küsimusele vastamiseks rakendati teooriale esmakordselt kovariantset Hamiltoni formalismi. See käsitlus on fundamentaalsel perspektiivil asjakohasem ja üldisem ning annab võimalust jõuda erinevate järeldusteni võrreldes kirjanduses levinud käsitlusega. f (TNGR ) teooria Hamiltoni analüüsi esimene osa on konkreetselt tuletatud. Käsitletud lähenemine avab teed kõige populaarsemate teleparalleelsete gravitatsiooniteooriate kanoonilisele Hamiltoni analüüsile. Väitekirja peamine järeldus näitab et f (TNGR ) teooria on tõsiselt kahtlustav, kuid on veel mõned aspektid mis on väärt uurida enne kui f (TNGR ) teooria on täielikult välistatud kui kooskõlaline gravitatsiooniteooria.For over a century, it has been known that gravity should be described by the theory of general relativity, in which matter is affecting the spacetime geometry we live in, rather than as a force theory. This description has been proven to pass much experimental and observational tests since Albert Einstein formulated this theory of gravity. Furthermore, it has been proven successful as incorporated in the standard model of cosmology. However, recently it has become evident from observation that there are statistically significant tensions in observations within the standard model of cosmology. Furthermore, 95% of our universe consists of dark matter and dark energy, which is still not understood. In order to address these issues one may look into modified theories of gravity. In this thesis teleparallel modified theories of gravity are examined. They make use of the fact that there are alternative physically equivalent descriptions of general relativity. However, the teleparallel formulation admits new ways to modify gravity. In particular a theory called f (TNGR )-gravity is examined. The question this thesis address is if f (TNGR )-gravity is viable as a theory from a theoretical point of view. In order to answer this question the so-called covariant Hamiltonian analysis of the theory is considered for the first time. This theory is more correct and general from a fundamental perspective and it might lead to different conclusions than for those found in the literature. The first part in the Hamiltonian analysis for f (TNGR )-gravity is explicitly derived. This paves the way for a canonical Hamiltonian analysis for the most popular theories of teleparallel gravity. The main conclusion of the thesis is that the viability of f (TNGR )-gravity is in serious doubt. Though, there are still a few points that need to be examined before ruling out f (TNGR ) as a viable theory of gravity.https://www.ester.ee/record=b545040

Some Early Geologists and Their Work in Montana

This paper marks an increased refinement and more detailed accuracy in the description of the geological features of the state. It includes the recent studies of mineral deposits, of oil structures, of the formations of bedded rocks and their included fossils, carried on both by the Federal and State governments and by various interested private persons, such as the mining companies. It is within this period that the Federal Government encouraged the U. S. Geological Survey in the publication of monographs on the National Parks, papers of great popular interest and educational value making these beautiful regions comprehensible in their geological features to the touring public

Soviet Objectives in the Eastern Mediterranean

Russian aspirations in the Eastern Mediterranean date back to Peter the Great. Turkey, lying athwart the Straits between the Black Sea and the Mediterranean, has often experienced Russian probes but has successfully resisted them with the alternating and occasionally combined support of Great Britain, France, and Germany

Calibration and characterization of the ELVIS hydrophones

Calibration is an important _eld and is used everywhere from education, research and industry. Every electrical equipment has to be calibrated during manufacturing and even over time as it is worn down. The purpose of calibration is to come as close as possible to the true value. The question is how close is close enough and how close is possible? Because even the equipment used for calibration needs calibrating, which in turn also needs calibrating and so on. This thesis will be about the hydrophones used by the system ELVIS. The method of choice is calibration by comparison. Its idea is to compare the signal received by the uncalibrated transducer with the same signal received by an already calibrated one. This might seem trivial but there are many things to be considered. ELVIS uses 47 hydrophones. The frequency range subjected to calibration is 30-250 kHz which leads to a huge amount of data to be recorded, analysed and presented. The result shows that each individual hydrophone performs similar to each other. Because of the insecurities regarding the reference hydrophone, no absolute measurements will be presented

Efficacy of MDMA-Assisted Psychotherapy in the Treatment of Chronic PTSD

Objective: To assess the effectiveness of MDMA-assisted psychotherapy in treating patients with chronic refractory PTSD using a systematic review. Methods: Literature search was performed on PubMed and PsychINFO using search terms “PTSD” and “MDMA” to identify randomized control trials within the past 10 years. Results: Two out of the three studies found statistically significant data in the treatment of refractory PTSD. Mithoefer, M. et al and Ot’alora, M. et. al found a statistically significant decrease in CAPS-IV total scores, decrease in depression symptoms, decreased in dissociative symptoms, and increase in sleep quality. Conclusion: The use of MDMA-assisted psychotherapy may be beneficial in treating chronic PTSD patients who have failed previous treatment methods. Additional studies with a larger sample size are necessary to determine the efficacy of MDMA-assisted psychotherapy in treating chronic PTSD