A
bstract
We propose a new radion stabilization mechanism in the Randall-Sundrum spacetime, introducing a bulk SU(
N
H
) gauge field which confines at a TeV scale. It turns out that the radion is ...stabilized by the balance between a brane tension and a pressure due to the Casimir energy of the strong SU(
N
H
) gauge field. We investigate the phase transition between the Randall-Sundrum (compactified) spacetime and a de-compactified spacetime and determine the parameter regime in which eternal (old) inflation is avoided and the phase transition can be completed. In comparison to the Goldberger-Wise mechanism, the 5D Planck mass can be larger than the AdS curvature and a classical description of the gravity is reliable in our stabilization mechanism. We also discuss the effect of the phase transition in cosmology such as an entropy dilution and a production of gravitational waves.
Exome sequencing has revealed the causative mutations behind numerous rare, inherited disorders, but it is challenging to find reliable epidemiological values for rare disorders. Here, I provide a ...genetic epidemiology method to identify the causative mutations behind rare, inherited disorders using two population exome sequences (1000 Genomes and NHLBI). I created global maps of carrier rate distribution for 18 recessive disorders in 16 diverse ethnic populations. Out of a total of 161 mutations associated with 18 recessive disorders, I detected 24 mutations in either or both exome studies. The genetic mapping revealed strong international spatial heterogeneities in the carrier patterns of the inherited disorders. I next validated this methodology by statistically evaluating the carrier rate of one well-understood disorder, sickle cell anemia (SCA). The population exome-based epidemiology of SCA African (allele frequency (AF) = 0.0454, N = 2447), Asian (AF = 0, N = 286), European (AF = 0.000214, N = 4677), and Hispanic (AF = 0.0111, N = 362) was not significantly different from that obtained from a clinical prevalence survey. A pair-wise proportion test revealed no significant differences between the two exome projects in terms of AF (46/48 cases; P > 0.05). I conclude that population exome-based carrier rates can form the foundation for a prospectively maintained database of use to clinical geneticists. Similar modeling methods can be applied to many inherited disorders.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
We explore the possibility that a confining first-order phase transition of a nearly-conformal dark sector generates the reported NANOGrav signal of a stochastic gravitational wave background. The ...visible Standard Model (SM) sector and the dark sector are initially thermally decoupled so that their temperatures are different. The nearly conformal phase transition is described by the shallow potential of a dilaton (or a radion in the 5D holographic perspective) generated by a new dark Yang-Mills field coupled to the conformal sector. For a dark sector only gravitationally connected with the visible sector, the NANOGrav signal is explained by the phase transition without contradicting the ΔNeff constraint, together with a contribution from supermassive black hole binaries. While the dilaton and dark glueballs can be produced after the phase transition, they immediately decay into dark radiation, which can help ameliorate the Hubble tension and be tested by the future CMB-S4 experiment. Alternatively, for a dark conformal sector decaying into the visible sector after the phase transition, the ΔNeff constraint is not applied and the phase transition can solely explain the NANOGrav signal.
The considerable range of genetic variation in human populations may partly reflect distinctive processes of adaptation to variable environmental conditions. However, the adaptive genomic signatures ...remain to be completely elucidated. This research explores candidate loci under selection at the population level by characterizing recently arisen premature termination codons (PTCs), some of which indicate a human knockout. From a total of 7595 participants from two population exome projects, 246 PTCs were found where natural selection has resulted in new alleles with a high frequency (from 1% to 96%) of derived alleles and various levels of population differentiation (FST = 0.00139-0.626). The PTC genes formed protein and regulatory networks limited to 15 biological processes or gene families, of which seven categories were previously unreported. PTC mutations have a strong tendency to be introduced into members of the same gene family, even during modern human evolution, although the exact nature of the selection is not fully known. The findings here suggest the ongoing evolutionary plasticity of modern humans at the genetic level and also partly provide insights into common human knockouts.
Phase transitions in twin Higgs models Fujikura, Kohei; Kamada, Kohei; Nakai, Yuichiro ...
The journal of high energy physics,
12/2018, Letnik:
2018, Številka:
12
Journal Article
Recenzirano
Odprti dostop
A
bstract
We study twin Higgs models at non-zero temperature and discuss cosmological phase transitions as well as their implications on electroweak baryogenesis and gravitational waves. It is shown ...that the expectation value of the Higgs field at the critical temperature of the electroweak phase transition is much smaller than the critical temperature, which indicates two important facts: (i) the electroweak phase transition cannot be analyzed perturbatively (ii) the electroweak baryogenesis is hardly realized in the typical realizations of twin Higgs models. We also analyze the phase transition associated with the global symmetry breaking, through which the Standard Model Higgs is identified with one of the pseudo-Nambu-Goldstone bosons in terms of its linear realization, with and without supersymmetry. For this phase transition, we show that, only in the supersymmetric case, there are still some parameter spaces, in which the perturbative approach is validated and the phase transition is the first order. We find that the stochastic gravitational wave background is generated through this first order phase transition, but it is impossible to be detected by DECIGO or BBO in the linear realization and the decoupling limit. The detection of stochastic gravitational wave background with the feature of first order phase transition, therefore, will give strong constraints on twin Higgs models.
A
bstract
We investigate cosmological phase transitions in various composite Higgs models consisting of four-dimensional asymptotically-free gauge field theories. Each model may lead to a ...confinement-deconfinement transition and a phase transition associated with the spontaneous breaking of a global symmetry that realizes the Standard Model Higgs field as a pseudo-Nambu-Goldstone boson. Based on the argument of universality, we discuss the order of the phase transition associated with the global symmetry breaking by studying the renormalization group flow of the corresponding linear sigma model at finite temperature, which is calculated by utilizing the
ϵ
-expansion technique at the one-loop order. Our analysis indicates that some composite Higgs models accommodate phenomenologically interesting first-order phase transitions. We also explore the confinement-deconfinement transition in a UV-completed composite Higgs model based on a Sp(2
N
c
) gauge theory. It is found that the first-order phase transition is favored when the number of degrees of freedom for the Sp(2
N
c
) gauge field is much larger than that of matter fields in the fundamental representation of Sp(2
N
c
). We comment on the gravitational wave signal generated by the confinement-deconfinement transition and its detectability at future observations. Our discussions motivate further studies on phase transitions in composite Higgs models with the use of lattice simulations.
A
bstract
We study the interaction of several types of static straight cosmic strings, including local strings, global strings, and bosonic superconducting strings with and without magnetic currents. ...First, we evaluate the interaction energy of two widely separated cosmic strings using the point source formalism and show that the most dominant contribution to the interaction energy comes from the excitation of the lightest mediator particles in a underlying theory. The interaction energy at arbitrary separation distances is then analyzed numerically by the gradient flow method. It turns out that an additional scalar field introduced in the bosonic superconducting string becomes an additional source of attraction. For such a bosonic superconducting string, we find that a string with two winding numbers is energetically favorable compared to two strings with a single winding number in a certain parameter region. Our analysis reveals that a phase structure of bosonic superconducting strings is richer than that of local and global strings and that the formation of bound states at intersections of bosonic superconducting strings is favored.
Familial Mediterranean fever (FMF) is an inherited disorder characterized by recurrent episodes of fever accompanied by sterile peritonitis, arthritis, and pleuritis. Many mutations in the MEFV gene ...have been identified as causing FMF. However, accompanying epidemiological information remains quite scarce except in some Mediterranean countries, and the degree of penetrance has been a subject of controversy. Here, I established a genetic epidemiology of full FMF mutations using two population exome studies. Of 57 mutations associated with FMF, 22 were detected in a total of 9007 individuals from two exome sequences. Exome‐based epidemiology revealed the carrier rates of FMF in 28 populations in 19 countries by individual mutation and showed strong population specificity for the MEFV mutations. Unexpectedly high carrier rates suggested that some mutations are benign variants with no pathological significance and highlighted the need for caution in analyzing MEFV mutations. Similar approach could be used to uncover the incomplete or no penetrance of mutations in most inherited disorders.
Here, I presented and validated the method for analyzing a genetic epidemiology of inherited disorders using population exome studies. Exome‐based epidemiology revealed the carrier rates of genetic disorders and provided a clue to uncover the incomplete or no penetrance of mutations in most inherited disorders.
PDF
