scholarly journals Characteristic class and the $\varepsilon $-factor of an étale sheaf

2020 ◽  
Vol 373 (10) ◽  
pp. 6887-6927
Author(s):  
Naoya Umezaki ◽  
Enlin Yang ◽  
Yigeng Zhao
Keyword(s):  
Characteristic Class

Stable cohomotopy and cobordism of abelian groups

1981 ◽  
Vol 90 (2) ◽  
pp. 273-278 ◽  
Author(s):  
C. T. Stretch
Keyword(s):  
Abelian Group ◽  
Abelian Groups ◽  
Finite Abelian Group ◽  
Formal Group ◽  
Characteristic Class ◽  
Burnside Ring ◽  
Classifying Space ◽  
Formal Group Law ◽  
Stable Cohomotopy ◽  
Group Law

The object of this paper is to prove that for a finite abelian group G the natural map is injective, where Â(G) is the completion of the Burnside ring of G and σ0(BG) is the stable cohomotopy of the classifying space BG of G. The map â is detected by means of an M U* exponential characteristic class for permutation representations constructed in (11). The result is a generalization of a theorem of Laitinen (4) which treats elementary abelian groups using ordinary cohomology. One interesting feature of the present proof is that it makes explicit use of the universality of the formal group law of M U*. It also involves a computation of M U*(BG) in terms of the formal group law. This may be of independent interest. Since writing the paper the author has discovered that M U*(BG) has previously been calculated by Land-weber(5).

scholarly journals Group actions and a vanishing characteristic class

Topology ◽  
1983 ◽  
Vol 22 (3) ◽  
pp. 237-240
Author(s):  
Lowell Jones
Keyword(s):  
Group Actions ◽  
Characteristic Class

Characteristic Class of Isotopy for Surfaces

2020 ◽  
Vol 33 (6) ◽  
pp. 2139-2156
Author(s):  
Yuxue Ren ◽  
Chengfeng Wen ◽  
Shengxian Zhen ◽  
Na Lei ◽  
Feng Luo ◽  
...  
Keyword(s):  
Characteristic Class

scholarly journals Chemical Compounds and Biologic Activities: A Review of Cedrela Genus

Molecules ◽  
2020 ◽  
Vol 25 (22) ◽  
pp. 5401
Author(s):  
Thalya Soares R. Nogueira ◽  
Michel de S. Passos ◽  
Lara Pessanha S. Nascimento ◽  
Mayara Barreto de S. Arantes ◽  
Noemi O. Monteiro ◽  
...  
Keyword(s):  
Wood Quality ◽  
Growth Inhibitor ◽  
Chemical Compounds ◽  
Characteristic Class ◽  
Economic Interest ◽  
Species Trees ◽  
Insect Growth ◽  
Phytochemical Studies

The genus Cedrela P. Browne, which belongs to the Meliaceae family, has eighteen species. Trees of this genus are of economic interest due to wood quality, as well as being the focus of studies because of relevant biologic activities as in other Meliaceae species. These activities are mainly related to limonoids, a characteristic class of compounds in this family. Therefore, the aim of this review is to perform a survey of the citations in the literature on the Cedrela genus species. Articles were found on quantitative and qualitative phytochemical studies of the Cedrela species, revealing the chemical compounds identified, such as aliphatics acid and alcohol, flavonoids, tocopherol, monoterpenes, sesquiterpenes, triterpenes, cycloartanes, steroids, and limonoids. Although some activities were tested, the majority of studies focused on the insecticidal, antifeedant, or insect growth inhibitor activities of this genus. Nonetheless, the most promising activities were related to their antimalarial and antitripanocidal effects, although further investigations are still needed.

THE SIGNATURE OF PARTIALLY DEFINED LOCAL COEFFICIENT SYSTEMS

2008 ◽  
Vol 17 (12) ◽  
pp. 1455-1481 ◽  
Author(s):  
MARKUS BANAGL
Keyword(s):  
Local System ◽  
Fiber Bundles ◽  
Characteristic Class ◽  
Intersection Homology ◽  
Entire Space ◽  
Singular Spaces ◽  
Codimension Two ◽  
Stratified Space ◽  
Stratified Pseudomanifold ◽  
Definition Of

Intersection homology enables the definition of a twisted signature of a stratified pseudomanifold with coefficients in a local system that is typically only given on the top stratum. If the local system extends to the entire space, then the twisted signature can be computed by a version of a characteristic class formula first observed by Atiyah for smooth fiber bundles. In the first part of this paper, we construct examples of singular spaces, equipped with local systems that do not extend, such that the above characteristic class formula fails. In the second part, we consider smooth codimension two embeddings of manifolds. We view the target as a stratified space with bottom stratum the image of the embedding and top stratum the complement. When the embedded manifold is a sphere, we establish various formulae that compute the twisted signature even when the local system does not extend from the top stratum to the entire space.

scholarly journals Wild ramification and the characteristic cycle of an ℓ-adic sheaf

2009 ◽  
Vol 8 (4) ◽  
pp. 769-829 ◽  
Author(s):  
Takeshi Saito
Keyword(s):  
Local Field ◽  
Cotangent Bundle ◽  
Euler Number ◽  
Residue Field ◽  
Geometric Method ◽  
Characteristic Class ◽  
Wild Ramification ◽  
Characteristic Cycle

AbstractWe propose a geometric method to measure the wild ramification of a smooth étale sheaf along the boundary. Using the method, we study the graded quotients of the logarithmic ramification groups of a local field of characteristic p > 0 with arbitrary residue field. We also define the characteristic cycle of an ℓ-adic sheaf, satisfying certain conditions, as a cycle on the logarithmic cotangent bundle and prove that the intersection with the 0-section computes the characteristic class, and hence the Euler number.

COMPUTING TWISTED SIGNATURES AND L-CLASSES OF NON-WITT SPACES

2006 ◽  
Vol 92 (2) ◽  
pp. 428-470 ◽  
Author(s):  
MARKUS BANAGL
Keyword(s):  
Characteristic Class ◽  
Joint Work ◽  
Stratified Space

In previous joint work with Cappell and Shaneson, we have established an Atiyah–Lusztig–Meyer-type multiplicative characteristic class formula for the twisted signature and, more generally, the twisted $L$-class, of a stratified Witt space. The present paper shows that these formulae hold even when the stratified space does not satisfy the Witt condition. It constitutes one of the first applications of signature homology.

scholarly journals Screening Carpet Substrate Interferences in Arson Identification by Solid Phase Microextraction and Gas Chromatography-Mass Spectrometry

Separations ◽  
2020 ◽  
Vol 7 (4) ◽  
pp. 63
Author(s):  
Alyssa Aldrich ◽  
Edna Gennarino-Lopez ◽  
Gabriel Odugbesi ◽  
Kaylandra Woodside ◽  
Shokouh Haddadi
Keyword(s):  
Mass Spectrometry ◽  
Gas Chromatography ◽  
Solid Phase Microextraction ◽  
Solid Phase ◽  
Gas Chromatography Mass Spectrometry ◽  
Characteristic Class ◽  
Pyrolysis Products ◽  
Chromatography Mass Spectrometry ◽  
Fire Debris ◽  
Fire Debris Analysis

The sample analysis and data interpretation is the most challenging step of fire debris analysis, due to the presence of combustion and pyrolysis products in the substrate material. In this study, a headspace solid phase microextraction (HS-SPME) procedure was applied to the extraction of combustion and pyrolysis products from three commonly used carpet substrate materials, made of nylon 6,6 and polyesters. Each carpet sample was burned with and without two different ignitable liquids (ILs), i.e., gasoline and kerosene, and the Total Ion Chromatograms (TICs) and Extracted Ion Profiles of characteristic class compounds of ILs were obtained and compared to those of unburned neat ILs, using gas-chromatography mass spectrometry (GC-MS), to study the possible interferences of these substrate materials in fire debris analysis.

Sign in / Sign up

Export Citation Format

Share Document