Attractive Lagrangians for Noncanonical Inflation

Treating inflation as an effective theory, we expect the effective Lagrangian to contain higher-dimensional kinetic operators suppressed by the scale of UV physics. When these operators are powers of the inflaton kinetic energy, the scalar field can support a period of noncanonical inflation which is smoothly connected to the usual slow-roll inflation. We show how to construct noncanonical inflationary solutions to the equations of motion for the first time, and demonstrate that noncanonical inflation is an attractor in phase space for all small- and large-field models. We identify some sufficient conditions on the functional form of the Lagrangian that lead to successful noncanonical inflation since not every Lagrangian with higher-dimensional kinetic operators can support noncanonical inflation. This extends the class of known viable Lagrangians and excludes many Lagrangians which do not work.Comment: 39 pages, 9 figures. v2. Fixed typos, added reference, small changes to examples; v3. Added discussion of field redefinitions, added references, matches published versio

Initial Conditions for Non-Canonical Inflation

We investigate the dynamics of homogeneous phase space for single-field models of inflation. Inflationary trajectories are formally attractors in phase space, but since in practice not all initial conditions lead to them, some degree of fine tuning is required for successful inflation. We explore how the dynamics of non-canonical inflation, which has additional kinetic terms that are powers of the kinetic energy, can play a role in ameliorating the initial conditions fine tuning problem. We present a qualitative analysis of inflationary phase space based on the dynamical behavior of the scalar field. This allows us to construct the flow of trajectories, finding that trajectories generically decay towards the inflationary solution at a steeper angle for non-canonical kinetic terms, in comparison to canonical kinetic terms, so that a larger fraction of the initial-conditions space leads to inflation. Thus, non-canonical kinetic terms can be important for removing the initial conditions fine-tuning problem of some small-field inflation models.Comment: 15 pages, 9 figure

Towards New Classes of Flux Compactifications

We derive novel solutions of flux compactification with D7-branes on the resolved conifold in type IIB String Theory and later extend this solution to allow for non-zero temperature. At zero temperature, we find that adding D7-branes via the Ouyang embedding contributes to the supersymmetry-breaking (1,2) imaginary-self-dual flux, without generating a bulk cosmological constant. We further find that having D7-branes and a resolved conifold together give rise to a non-trivial D-term on the D7-branes. This supersymmetry-breaking term vanishes when we take the singular conifold limit, although supersymmetry appears to remain broken. We also lift our construction to F-theory where we show that the type IIB (1,2) flux goes to (2,2) non-primitive flux on the fourfold. In the second part of the thesis, we extend these results by taking the non-extremal limit of our geometry to incorporate temperature. In this case, the internal NS-NS and R-R fluxes are no longer expected to be self-dual, but they should also naturally be extensions of the fluxes found above. From the supergravity equations of motion, we compute how the new contributions to the fluxes should enter, due to the squashing of the resolved metric and non-extremality. This provides us with a compelling gravity dual of large N thermal quantum chromodynamics with flavor.Comment: 111 pages, 7 figures, PhD thesi

Toward the Gravity Dual of Heterotic Small Instantons

The question of what happens when the heterotic SO(32) instanton becomes small was answered sometime back by Witten. The heterotic theory develops an enhanced Sp(2k) gauge symmetry for k small instantons, besides the allowed SO(32) gauge symmetry. An interesting question now is to ask what happens when we take the large k limit. In this paper we argue that in some special cases, where Gauss' law allows the large k limit, the dynamics of the large k small instantons can be captured by a dual gravitational description. For the cases that we elaborate in this paper, the gravity duals are non-Kahler manifolds although in general they could be non-geometric. These small instantons are heterotic five-branes and the duality allows us to study the strongly coupled field theories on these five-branes. We review and elaborate on some of the recent observations pointing towards this duality, and argue that in certain cases the gauge/gravity duality may be understood as small instanton transitions under which the instantons smoothen out and consequently lose the Sp(2k) gauge symmetry. This may explain how branes disappear on the dual side and are replaced by fluxes. We analyse the torsion classes before and after the transitions, and discuss briefly how the ADHM sigma model and related vector bundles could be studied for these scenarios.Comment: 47 pages, 3 eps figures, LaTex, JHEP3 file; v2: Another consistency check added, typos corrected and a reference added; v3: Text expanded a bit, minor typos corrected and a few references updated. Final version to appear in Phys. Rev.

Could it be sepsis?: Clinical tools in order to detect suspected sepsis in emergency rooms

Introduksjon: I 2016 ble sepsis definert som «en livstruende tilstand som oppstår når kroppens reaksjon på en infeksjon medfører organsvikt». I Norge har rundt 55 000 innlagte pasienter sepsis hvert år og mortaliteten er på omtrent 15%. Rask og målrettet behandling er avgjørende for å redusere mortaliteten. I 2016-2018 så helsetilsynet at sikkerheten til disse pasientene var for dårlig i norske akuttmottak. For å fange opp pasienter med mistanke om sepsis er det laget kliniske verktøy. Denne oppgaven vil se nærmere på det sepsis spesifikke skåringsverktøyet QuickSOFA(qSOFA) og sette det opp mot det mer generelle skåringsverktøyet National early warning score (NEWS) til å identifisere sepsis i akuttmottak. Problemstilling: Er NEWS et bedre skåringsverktøy enn qSOFA til å fange opp pasienter med mistanke om sepsis ved ankomst akuttmottak? Metode: Oppgaven er gjennomført som en litteraturstudie. Det er gjennomført et systematisk søk i CINAHL og Pubmed, hvor det er hentet ut åtte fagfellevurderte primærartikler for å kunne besvare oppgavens problemstilling. Resultat: Ved gjennomgang av åtte artikler viser NEWS at den i hovedsak har høyere diskrimineringsevne, høyere sensitivitet og lavere spesifisitet enn qSOFA. Studiene har sine begrensninger og det er enkelte forskjeller dem imellom. Konklusjon: Etter gjennomgang av åtte artikler viser funnene at NEWS i hovedsak har høyere evne enn qSOFA til å fange opp pasienter med mistanke om sepsis ved ankomst akuttmottak. Disse funnene viser at NEWS gjennomgående har høyere diskrimineringsevne og sensitivitet. qSOFA derimot, har høyere spesifisitet enn NEWS. Det er også stilt spørsmålstegn i enkelte studier om det er behov for qSOFA i akuttmottaket, hvis NEWS allerede er implementert