74 research outputs found
On -gaps between zeros of the Riemann zeta-function
Under the Riemann Hypothesis, we prove for any natural number there exist
infinitely many large natural numbers such that
and
for
explicit absolute positive constants and , where
denotes an ordinate of a zero of the Riemann zeta-function on the critical
line. Selberg published announcements of this result several times but did not
include a proof. We also suggest a general framework which might lead to
stronger statements concerning the vertical distribution of nontrivial zeros of
the Riemann zeta-function.Comment: to appear in the Bulletin of the London Mathematical Societ
An effective Chebotarev density theorem for families of number fields, with an application to -torsion in class groups
We prove a new effective Chebotarev density theorem for Galois extensions
that allows one to count small primes (even as small as an
arbitrarily small power of the discriminant of ); this theorem holds for the
Galois closures of "almost all" number fields that lie in an appropriate family
of field extensions. Previously, applying Chebotarev in such small ranges
required assuming the Generalized Riemann Hypothesis. The error term in this
new Chebotarev density theorem also avoids the effect of an exceptional zero of
the Dedekind zeta function of , without assuming GRH. We give many different
"appropriate families," including families of arbitrarily large degree. To do
this, we first prove a new effective Chebotarev density theorem that requires a
zero-free region of the Dedekind zeta function. Then we prove that almost all
number fields in our families yield such a zero-free region. The innovation
that allows us to achieve this is a delicate new method for controlling zeroes
of certain families of non-cuspidal -functions. This builds on, and greatly
generalizes the applicability of, work of Kowalski and Michel on the average
density of zeroes of a family of cuspidal -functions. A surprising feature
of this new method, which we expect will have independent interest, is that we
control the number of zeroes in the family of -functions by bounding the
number of certain associated fields with fixed discriminant. As an application
of the new Chebotarev density theorem, we prove the first nontrivial upper
bounds for -torsion in class groups, for all integers ,
applicable to infinite families of fields of arbitrarily large degree.Comment: 52 pages. This shorter version aligns with the published paper. Note
that portions of Section 8 of the longer v1 have been developed as a separate
paper with identifier arXiv:1902.0200
An effective Chebotarev density theorem for families of fields, with an application to class groups
This talk will present an effective Chebotarev theorem that holds for all but a possible zero-density subfamily of certain families of number fields of fixed degree. For certain families, this work is unconditional, and in other cases it is conditional on the strong Artin conjecture and certain conjectures on counting number fields. As an application, we obtain nontrivial average upper bounds on ℓ-torsion in the class groups of the families of fields
Consecutive primes in tuples
In a recent advance towards the Prime -tuple Conjecture, Maynard and Tao
have shown that if is sufficiently large in terms of , then for an
admissible -tuple of linear forms in
, the set contains at
least primes for infinitely many . In this note, we
deduce that contains at least
consecutive primes for infinitely many . We answer an old
question of Erd\H os and Tur\'an by producing strings of consecutive
primes whose successive gaps form an increasing
(resp. decreasing) sequence. We also show that such strings exist with
for . For any coprime integers
and we find arbitrarily long strings of consecutive primes with bounded
gaps in the congruence class .Comment: Revised versio
Microgenomic approaches to identify clinically relevant gene signatures that discriminate histologic types of breast carcinomas.
Background: Breast cancer presents itself in a variety of histologic types, and the two most common types are invasive ductal carcinoma (IDC) and invasive lobular carcinoma (ILC). Based on comparative genomic hybridization (CGH) analyses, ILC is more closely related to low grade IDC than it is to intermediate and high grade IDC. Results from the BIG 1-98 trial demonstrate that post-menopausal women who are affected with estrogen receptor positive (ER+) ILC or luminal B (high grade) IDC experience a greater magnitude of benefit when they are treated with the aromatase inhibitor (AI) letrozole compared to treatment with the antiestrogen tamoxifen. To contrast, it has been found in the same trial that women affected with luminal A (low grade) IDC experience more benefit when treated with tamoxifen when compared to letrozole. It is therefore imperative to accurately distinguish low grade IDC from ILC considering their varying responses to adjuvant treatment. Despite genetic evidence suggesting a close relationship between ILC and low grade IDC, a clinically relevant gene set underlying a tumor’s biologic responsiveness to letrozole likely exists. The goal of this study is to use microgenomics to identify a clinically relevant candidate gene set that would discriminate between ILC and low grade IDC rather than relying solely on histomorphology and/or immunohistochemistry for the pathologic diagnosis, especially when conventional tests are conflicting. Methods: Using 247 de-identified human breast carcinoma biopsies collected under standardized, stringent conditions, total RNA was extracted from carcinoma cells procured by laser capture microdissection to perform microarray analyses of approximately 22,000 genes to identify expression signatures associated with breast cancer characteristics. Of the 247 LCM-procured samples, 14 were ER+ ILC, 9 were ER+ low grade IDC, and 43 were ER+ high grade IDC. The other 181 samples were either ER- or of another cancer type other than ILC and IDC. Candidate genes were selected by identifying those that were differentially expressed between ILC and low grade IDC (luminal A) and at the same time, had similar expression levels between ILC and high grade IDC (luminal B). qPCR analyses of whole tissue samples were then utilized to validate the selected gene set. Results: Comparison of microarray data from hormone receptor positive tumors yielded 299 probes that were differentially expressed (p0.01) between ILC and high grade IDC (luminal B). 11 of these 99 genes were initially chosen for further investigation by performing qPCR on whole tissue samples from 21 ILC, 19 low grade IDC and 19 high grade IDC tumors. Our initial analysis revealed expression of the gene coding for heparin-binding EGF like growth factor (HBEGF) and collapsin response mediator protein 1 (CRMP1) may be potential markers for differentiating between ILC and low grade (luminal A) IDC
Petrology of the Lower Middle Cambrian Langston Formation, North-Central Utah and Southeastern Idaho
The Lower Middle Cambrian Langson Formation was studied in the xi Bear River Range of north-central Utah and southeasternmost Idaho and the Wellsville Mountains of north-central Utah. The depositional textures and sedimentary structures preserved within the rocks were compared with characteristics of similar modern sediments and ancient rock to determine environments of deposition, paleogeography, diagenetic alteration and pattern of dolomitization.
The rocks of the Langston Formation were divided into eleven different rock types. These eleven rock types were formed within four recognizable lithofacies: 1) upper peritidal; 2) inner carbonate shelf; 3) inner clastic shelf; and 4) outer clastic shelf.
The general depositional environment is inferred to have been a shall ow subtidal to subaerial carbonate shoal complex. Clastic sediments from the east and north or northwest periodically prograded over the carbonate complex during times of relatively slow subsidence. The deposition of the Langston Formation mudrocks and carbonates occurred during the first Cambrian grand cycle.
Eogenetic diagenetic features include birdseye structures, relict evaporite structures, fibrous rim cement, compaction, and the begining of dolomitization. Mesogenetic diagenesis is characterized by dolomitization and pressure solution. Telogenetic diagenesis is limited to fracturing and calcite infilling.
Dolomitization is believed to have resulted mainly from downward reflux of hypersaline brines, as indicated by relict evaporite structures, zoned dolomite rhombs, and a general association of dolomite with upper peritidal facies. The hypersaline brines formed in the upper peritidal environment, and percolated downward through underlying porous sediments. The greater density of the hypersaline brines displaced less-dense interstitial fluids. These brines were periodically diluted by normal marine water or fresh water
Extremal primes for elliptic curves without complex multiplication
Fix an elliptic curve E over Q. An extremal prime for E is a prime p of good reduction such that the number of rational points on E modulo p is maximal or minimal in relation to the Hasse bound. Assuming that all the symmetric power L-functions associated to E are automorphic and satisfy the Generalized Riemann Hypothesis, we give the first non-trivial upper bounds for the number of such primes when E is a curve without complex multiplication. In order to obtain this bound, we use explicit equidistribution for the Sato-Tate measure as in the work of Rouse and Thorner (arXiv:1305.5283) and refine certain intermediate estimates taking advantage of the fact that extremal primes have a very small Sato-Tate measure
Development and Validation of an Instrument to Measure Moral Distress Among Counselors Working with Children and Adolescents
Falender and Shafranske (2004) stated it is “essential for clinicians to develop and understanding of all the influences, from conscious beliefs and culturally embedded values to unresolved conflicts at the margin of awareness, that contribute to clinical practice” (p. 81). The purpose of this study was to meet this professional imperative by developing an instrument designed to assess moral distress among counselors working with children and/or adolescents. Using open-ended surveys and semi-structured interviews, detailed descriptions of participants’ experiences of moral distress were obtained in order to gain an initial understanding of the ways in which the phenomeonon is experienced in the context of counseling. Based on these participants’ experiences, a thematic structure was identified, from which an initial item pool was generated. A 106-item instrument was constructed, which was pilot tested with two samples, one consisting of counselors and counselor educators used to assess item and sub-theme representativeness and acceptability, and the other of laypersons used to assess non-validity issues. Inter-rater agreeability and qualitative feedback was analyzed to arrive at a parsimonious instrument that demonstrated acceptable content and face validity. As a result, a modified instrument consisting of 63 items was finalized, which assesses moral distress across eight domains, and demonstrates promising validiy overall
On a conjecture for -torsion in class groups of number fields: from the perspective of moments
It is conjectured that within the class group of any number field, for every integer , the -torsion subgroup is very small (in an appropriate sense, relative to the discriminant of the field). In nearly all settings, the full strength of this conjecture remains open, and even partial progress is limited. Significant recent progress toward average versions of the -torsion conjecture has crucially relied on counts for number fields, raising interest in how these two types of question relate. In this paper we make explicit the quantitative relationships between the -torsion conjecture and other well-known conjectures: the Cohen-Lenstra heuristics, counts for number fields of fixed discriminant, counts for number fields of bounded discriminant (or related invariants), and counts for elliptic curves with fixed conductor. All of these considerations reinforce that we expect the -torsion conjecture is true, despite limited progress toward it. Our perspective focuses on the relation between pointwise bounds, averages, and higher moments, and demonstrates the broad utility of the "method of moments.
Benford Behavior of Zeckendorf Decompositions
A beautiful theorem of Zeckendorf states that every integer can be written
uniquely as the sum of non-consecutive Fibonacci numbers . A set is said to satisfy Benford's law if
the density of the elements in with leading digit is
; in other words, smaller leading digits are more
likely to occur. We prove that, as , for a randomly selected
integer in the distribution of the leading digits of the
Fibonacci summands in its Zeckendorf decomposition converge to Benford's law
almost surely. Our results hold more generally, and instead of looking at the
distribution of leading digits one obtains similar theorems concerning how
often values in sets with density are attained.Comment: Version 1.0, 12 pages, 1 figur
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