scholarly journals A Global Poincaré inequality on Graphs via a Conical Curvature-Dimension Condition

2018 ◽  
Vol 6 (1) ◽  
pp. 32-47 ◽  
Author(s):  
Sajjad Lakzian ◽  
Zachary Mcguirk
Keyword(s):  
Lower Bound ◽  
Sharp Estimate ◽  
Sufficient Conditions ◽  
Poincaré Inequality ◽  
Complete Graphs ◽  
Poincare Inequality ◽  
Underlying Graph ◽  
Dimension Analysis ◽  
Necessary And Sufficient ◽  
Sharp Lower Bound

Abstract We introduce and study the conical curvature-dimension condition, CCD(K, N), for finite graphs.We show that CCD(K, N) provides necessary and sufficient conditions for the underlying graph to satisfy a sharp global Poincaré inequality which in turn translates to a sharp lower bound for the first eigenvalues of these graphs. Another application of the conical curvature-dimension analysis is finding a sharp estimate on the curvature of complete graphs

Capacity and Compactness Criteria

2018 ◽  
Author(s):  
D. E. Edmunds ◽  
W. D. Evans
Keyword(s):  
Discrete Spectrum ◽  
Sufficient Conditions ◽  
Poincaré Inequality ◽  
Necessary And Sufficient Conditions ◽  
Poincare Inequality ◽  
Necessary And Sufficient ◽  
Bounded Below

In this chapter, necessary and sufficient conditions are derived for the Poincaré inequality to hold, for the embedding of W01,p(Ω) in Lp(Ω‎) to be compact, and for a self-adjoint realization of − aijDiDj + q to have a wholly discrete spectrum when q is real and bounded below. The results are proved using a method of Maz’ya.

scholarly journals On size multipartite Ramsey numbers for stars

2020 ◽  
Vol 3 (2) ◽  
pp. 109
Author(s):  
Anie Lusiani ◽  
Edy Tri Baskoro ◽  
Suhadi Wido Saputro
Keyword(s):  
Lower Bound ◽  
Disjoint Union ◽  
Sufficient Conditions ◽  
Necessary And Sufficient Conditions ◽  
Ramsey Number ◽  
Complete Graphs ◽  
Ramsey Numbers ◽  
Simple Graphs ◽  
Multipartite Graphs ◽  
Necessary And Sufficient

<p>Burger and Vuuren defined the size multipartite Ramsey number for a pair of complete, balanced, multipartite graphs <em>mj</em>(<em>Ka</em>x<em>b</em>,<em>Kc</em>x<em>d</em>), for natural numbers <em>a,b,c,d</em> and <em>j</em>, where <em>a,c</em> &gt;= 2, in 2004. They have also determined the necessary and sufficient conditions for the existence of size multipartite Ramsey numbers <em>mj</em>(<em>Ka</em>x<em>b</em>,<em>Kc</em>x<em>d</em>). Syafrizal <em>et al</em>. generalized this definition by removing the completeness requirement. For simple graphs <em>G</em> and <em>H</em>, they defined the size multipartite Ramsey number <em>mj</em>(<em>G,H</em>) as the smallest natural number <em>t</em> such that any red-blue coloring on the edges of <em>Kj</em>x<em>t</em> contains a red <em>G</em> or a blue <em>H</em> as a subgraph. In this paper, we determine the necessary and sufficient conditions for the existence of multipartite Ramsey numbers <em>mj</em>(<em>G,H</em>), where both <em>G</em> and <em>H</em> are non complete graphs. Furthermore, we determine the exact values of the size multipartite Ramsey numbers <em>mj</em>(<em>K</em>1,<em>m</em>, <em>K</em>1,<em>n</em>) for all integers <em>m,n &gt;= </em>1 and <em>j </em>= 2,3, where <em>K</em>1,<em>m</em> is a star of order <em>m</em>+1. In addition, we also determine the lower bound of <em>m</em>3(<em>kK</em>1,<em>m</em>, <em>C</em>3), where <em>kK</em>1,<em>m</em> is a disjoint union of <em>k</em> copies of a star <em>K</em>1,<em>m</em> and <em>C</em>3 is a cycle of order 3.</p>

On the factorable spaces of absolutely p-summable, null, convergent, and bounded sequences

2021 ◽  
Vol 71 (6) ◽  
pp. 1375-1400
Author(s):  
Feyzi Başar ◽  
Hadi Roopaei
Keyword(s):  
Lower Bound ◽  
Sequence Space ◽  
Sufficient Conditions ◽  
Necessary And Sufficient Conditions ◽  
Matrix Transformations ◽  
Infinite Matrix ◽  
The Matrix ◽  
Alpha Beta ◽  
Necessary And Sufficient ◽  
Bounded Sequences

Abstract Let F denote the factorable matrix and X ∈ {ℓp , c 0, c, ℓ ∞}. In this study, we introduce the domains X(F) of the factorable matrix in the spaces X. Also, we give the bases and determine the alpha-, beta- and gamma-duals of the spaces X(F). We obtain the necessary and sufficient conditions on an infinite matrix belonging to the classes (ℓ p (F), ℓ ∞), (ℓ p (F), f) and (X, Y(F)) of matrix transformations, where Y denotes any given sequence space. Furthermore, we give the necessary and sufficient conditions for factorizing an operator based on the matrix F and derive two factorizations for the Cesàro and Hilbert matrices based on the Gamma matrix. Additionally, we investigate the norm of operators on the domain of the matrix F. Finally, we find the norm of Hilbert operators on some sequence spaces and deal with the lower bound of operators on the domain of the factorable matrix.

Weighted Simplex Procedures for Determining Boundary Points and Constants for the Univariate and Multivariate Power Methods

2000 ◽  
Vol 25 (4) ◽  
pp. 417-436 ◽  
Author(s):  
Todd C. Headrick ◽  
Shlomo S. Sawilowsky
Keyword(s):  
Standard Deviation ◽  
Lower Bound ◽  
Lagrange Multiplier ◽  
Sufficient Conditions ◽  
Efficient Algorithms ◽  
Data Sets ◽  
Transformation Techniques ◽  
Normal Distributions ◽  
Nonnormal Distributions ◽  
Necessary And Sufficient

The power methods are simple and efficient algorithms used to generate either univariate or multivariate nonnormal distributions with specified values of (marginal) mean, standard deviation, skew, and kurtosis. The power methods are bounded as are other transformation techniques. Given an exogenous value of skew, there is an associated lower bound of kurtosis. Previous approximations of the boundary for the power methods are either incorrect or inadequate. Data sets from education and psychology can be found to lie within, near, or outside tile boundary of the power methods. In view of this, we derived necessary and sufficient conditions using the Lagrange multiplier method to determine the boundary of the power methods. The conditions for locating and classifying modes for distributions on the boundary were also derived. Self-contained interactive Fortran programs using a Weighted Simplex Procedure were employed to generate tabled values of minimum kurtosis for a given value of skew and power constants for various (non)normal distributions.

scholarly journals Lower Bound of Sectional Curvature of Manifold of Beta Distributions and Complete Monotonicity of Functions Involving Polygamma Functions

2020 ◽  
Author(s):  
Feng Qi
Keyword(s):  
Lower Bound ◽  
Sectional Curvature ◽  
Sufficient Conditions ◽  
Laplace Transforms ◽  
Complete Monotonicity ◽  
Convolution Theorem ◽  
Open Problems ◽  
Polygamma Functions ◽  
Beta Distributions ◽  
Necessary And Sufficient

In the paper, by convolution theorem for the Laplace transforms and analytic techniques, the author finds necessary and sufficient conditions for complete monotonicity, monotonicity, and inequalities of several functions involving polygamma functions. By these results, the author derives a lower bound of a function related to the sectional curvature of the manifold of the beta distributions. Finally, the author poses several guesses and open problems related to monotonicity, complete monotonicity, and inequalities of several functions involving polygamma functions.

A Network-Flow Feasibility Theorem and Combinatorial Applications

1959 ◽  
Vol 11 ◽  
pp. 440-451 ◽  
Author(s):  
D. R. Fulkerson
Keyword(s):  
Lower Bound ◽  
Upper Bound ◽  
Network Flow ◽  
Present Author ◽  
Sufficient Conditions ◽  
Necessary And Sufficient Conditions ◽  
Private Communication ◽  
Circulatory Flow ◽  
Necessary And Sufficient ◽  
Circulation Theorem

There are a number of interesting theorems, relative to capacitated networks, that give necessary and sufficient conditions for the existence of flows satisfying constraints of various kinds. Typical of these are the supply-demand theorem due to Gale (4), which states a condition for the existence of a flow satisfying demands at certain nodes from supplies at other nodes, and the Hoffman circulation theorem (received by the present author in private communication), which states a condition for the existence of a circulatory flow in a network in which each arc has associated with it not only an upper bound for the arc flow, but a lower bound as well. If the constraints on flows are integral (for example, if the bounds on arc flows for the circulation theorem are integers), it is also true that integral flows meeting the requirements exist provided any flow does so.

scholarly journals Packings and Coverings of Various Complete Graphs with the 4-Cycle with a Pendant Edge

2013 ◽  
Vol 2013 ◽  
pp. 1-8 ◽  
Author(s):  
Brandon Coker ◽  
Gary D. Coker ◽  
Robert Gardner ◽  
Yan Xia
Keyword(s):  
Sufficient Conditions ◽  
Bipartite Graphs ◽  
Necessary And Sufficient Conditions ◽  
Complete Graphs ◽  
Complete Bipartite Graphs ◽  
Necessary And Sufficient

We consider the packings and coverings of complete graphs with isomorphic copies of the 4-cycle with a pendant edge. Necessary and sufficient conditions are given for such structures for (1) complete graphs , (2) complete bipartite graphs , and (3) complete graphs with a hole . In the last two cases, we address both restricted and unrestricted coverings.

scholarly journals On γ-Sets in Rings

2021 ◽  
Vol 14 (1) ◽  
pp. 314-326
Author(s):  
Eva Jenny C. Sigasig ◽  
Cristoper John S. Rosero ◽  
Michael Jr. Patula Baldado
Keyword(s):  
Lower Bound ◽  
Division Ring ◽  
Upper Bound ◽  
Sufficient Conditions ◽  
Necessary And Sufficient Conditions ◽  
Minimum Cardinality ◽  
Division Rings ◽  
Necessary And Sufficient

Let R be a ring with identity 1R. A subset J of R is called a γ-set if for every a ∈ R\J,there exist b, c ∈ J such that a+b = 0 and ac = 1R = ca. A γ-set of minimum cardinality is called a minimum γ-set. In this study, we identified some elements of R that are necessarily in a γ-sets, and we presented a method of constructing a new γ-set. Moreover, we gave: necessary and sufficient conditions for rings to have a unique γ-set; an upper bound for the total number of minimum γ-sets in a division ring; a lower bound for the total number of minimum γ-sets in a division ring; necessary and sufficient conditions for T(x) and T to be equal; necessary and sufficient conditions for a ring to have a trivial γ-set; necessary and sufficient conditions for an image of a γ-set to be a γ-set also; necessary and sufficient conditions for a ring to have a trivial γ-set; and, necessary and sufficient conditions for the families of γ-sets of two division rings to be isomorphic.

scholarly journals TAX RULES TO PREVENT EXPECTATIONS-DRIVEN LIQUIDITY TRAPS

2021 ◽  
pp. 1-24
Author(s):  
Yoichiro Tamanyu
Keyword(s):  
Lower Bound ◽  
Government Spending ◽  
Multiple Equilibria ◽  
Sufficient Conditions ◽  
New Keynesian ◽  
Inflation Expectations ◽  
Liquidity Trap ◽  
Tax Rate ◽  
New Keynesian Models ◽  
Necessary And Sufficient

Multiple equilibria arise in standard New Keynesian models when the nominal interest rate is set according to the Taylor rule and constrained by a zero lower bound (ZLB). One of these equilibria is deflationary and referred to as an expectations-driven liquidity trap (ELT) as it arises because of the de-anchoring of inflation expectations. This study demonstrates that a simple tax rule responding to inflation can prevent a liquidity trap from arising without increasing government spending or debt. We analytically investigate the necessary and sufficient conditions to prevent an ELT and show that both the frequency and persistence of ELT episodes affect the extent to which the tax rule must respond to inflation. In brief, the higher the frequency or the longer the persistence of the ELT, the greater the response of the tax rate must be.

scholarly journals A-optimal chemical balance weighing design under certain condition

2007 ◽  
Vol 4 (1) ◽  
Author(s):  
Bronisław Ceranka ◽  
Małgorzata Graczyk
Keyword(s):  
Lower Bound ◽  
Sufficient Conditions ◽  
Design Matrix ◽  
Block Designs ◽  
Chemical Balance ◽  
Incidence Matrices ◽  
Construction Methods ◽  
New Construction ◽  
The Right ◽  
Necessary And Sufficient

The paper is studying the estimation problem of individual weights of \(p\) objects using the design matrix \(\mathbf{X}\) of the A-optimal chemical balance weighing design under the restriction \(p_1 + p_2 = q  \leq p\), where \(p_1\) and \(p_2\) represent the number of objects placed on the left pan and on the right pan, respectively, in each of the measurement operations. The lower bound of \(\mathrm{Tr}(\mathbf{X}^{\prime}\mathbf{X})^{-1}\) is attained and the necessary and sufficient conditions for this lower bound to be obtained are given. There are given new construction methods of the A-optimal chemical balance weighing designs based on incidence matrices of the balanced bipartite weighing designs and the ternary balanced block designs.

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