The closure of Gdenoted by cl(G),is obtained by recursively performing the local completion operation at eligible vertices as long as possible.The core of H is the graph co(H)obtained from H by deleting all the vertic...The closure of Gdenoted by cl(G),is obtained by recursively performing the local completion operation at eligible vertices as long as possible.The core of H is the graph co(H)obtained from H by deleting all the vertices of degree 1,and replacing the path xyz by the edge xz for each y of degree 2.In this paper,we discuss the Hamiltonicity of 3-connected claw-free graph under domination number and clique covering,and the Hamiltonicity of the 3-connected claw-free and hourglass-free graphs under domination number.We show that:(1)G is hamiltonian or cl(G)=L(H),and co(H)can be contracted to the Petersen graph if G is a 3-connected claw-free graph and thedomination number ofG is at most 6;(2)G is hamiltonian or cl(G)=L(H),where the reduction ofco(H)is a member of{P,P(14)},if G is a 3-connected claw-free,hourglass-free graph with domination number at most 11;(3)G is hamiltonian or cl(G)=L(H),and co(H)can becontracted to the Petersen graph,if G is a 3-connected claw-free graph with clique covering number at most 12.展开更多
Outer-independent Roman domination on graphs originates from the defensive strategy of Ancient Rome,which is that if any city without an army is attacked,a neighboring city with two armies could mobilize an army to su...Outer-independent Roman domination on graphs originates from the defensive strategy of Ancient Rome,which is that if any city without an army is attacked,a neighboring city with two armies could mobilize an army to support it and any two cities that have no army cannot be adjacent.The outer-independent Roman domination on graphs is an attractive topic in graph theory,and the definition is described as follows.Given a graph G=(V,E),a function f:V(G)→{0,1,2}is an outer-independent Roman dominating function(OIRDF)if f satisfies that every vertex v∈V with f(v)=0 has at least one adjacent vertex u∈N(v)with f(u)=2,where N(v)is the open neighborhood of v,and the set V0={v|f(v)=0}is an independent set.The weight of an OIRDF f is w(f)=∑v∈Vf(v).The value of minf w(f)is the outerindependent Roman domination number of G,denoted asγoiR(G).This paper is devoted to the study of the outer-independent Roman domination number of the Cartesian product of paths Pn□Pm.With the help of computer,we find some recursive OIRDFs and then we present an upper bound ofγoiR(Pn□Pm).Furthermore,we prove the lower bound ofγoiR(Pn□Pm)(n≤3)is equal to the upper bound.Hence,we achieve the exact value ofγoiR(Pn□Pm)for n≤3 and the upper bound ofγoiR(Pn□Pm)for n≥4.展开更多
Consider a graph G=(V,E).A perfect double Roman dominating function(PDRDF for short)is a function h:V→{0,1,2,3}that satisfies the condition∑y∈NG[x],h(y≥1)h(y)=|{y∈NG(x):h(y)≥1}|+2 for any x∈V with h(x)≤1.Th...Consider a graph G=(V,E).A perfect double Roman dominating function(PDRDF for short)is a function h:V→{0,1,2,3}that satisfies the condition∑y∈NG[x],h(y≥1)h(y)=|{y∈NG(x):h(y)≥1}|+2 for any x∈V with h(x)≤1.The weightω(h)of this function is∑y∈Vh(y).The perfect double Roman domination number(PDRD-number)of G,denoted byγdRp(G),is defined as the minimum weight among all PDRDFs of G.This article presents a comprehensive analysis of the PDRD-number of connected cographs,demonstrating that it falls within the set{2,3,4,5,6}.Furthermore,it establishes that for any integer i≥7,there is a connected cograph G such that its PDRD-number is equal to i.展开更多
LetΩbe homogeneous of degree zero,integrable on Sd−1 and have vanishing moment of order one,a be a function on Rd such that ∇a∈L∞(Rd).Let T*Ω,a be the maximaloperator associated with the d-dimensional...LetΩbe homogeneous of degree zero,integrable on Sd−1 and have vanishing moment of order one,a be a function on Rd such that ∇a∈L∞(Rd).Let T*Ω,a be the maximaloperator associated with the d-dimensional Calder´on commutator defined by T*Ωaf(x):=supε>0|∫|x-y|>ε^Ω(x-y)/|x-y|d+1(a(x)-a(y))f(y)dy.In this paper,the authors establish bilinear sparse domination for T*Ω,a under the assumption Ω∈L∞(Sd−1).As applications,some quantitative weighted bounds for T*Ω,a are obtained.展开更多
The Roman domination problem is an important combinatorial optimization problem that is derived from an old story of defending the Roman Empire and now regains new significance in cyber space security,considering back...The Roman domination problem is an important combinatorial optimization problem that is derived from an old story of defending the Roman Empire and now regains new significance in cyber space security,considering backups in the face of a dynamic network security requirement.In this paper,firstly,we propose a Roman domination game(RDG)and prove that every Nash equilibrium(NE)of the game corresponds to a strong minimal Roman dominating function(S-RDF),as well as a Pareto-optimal solution.Secondly,we show that RDG is an exact potential game,which guarantees the existence of an NE.Thirdly,we design a game-based synchronous algorithm(GSA),which can be implemented distributively and converge to an NE in O(n)rounds,where n is the number of vertices.In GSA,all players make decisions depending on local information.Furthermore,we enhance GSA to be enhanced GSA(EGSA),which converges to a better NE in O(n2)rounds.Finally,we present numerical simulations to demonstrate that EGSA can obtain a better approximate solution in promising computation time compared with state-of-the-art algorithms.展开更多
A dominating set D in a graph G is called an injective equitable dominating set (Inj-equitable dominating set) if for every , there exists such that u is adjacent to v and . The minimum cardinality of such a dominatin...A dominating set D in a graph G is called an injective equitable dominating set (Inj-equitable dominating set) if for every , there exists such that u is adjacent to v and . The minimum cardinality of such a dominating set is denoted by and is called the Inj-equitable domination number of G. In this paper, we introduce the injective equitable domination of a graph and study its relation with other domination parameters. The minimal injective equitable dominating set, the injective equitable independence number , and the injective equitable domatic number are defined.展开更多
A function f:E(G)→{−1,1}is called a signed edge dominating function(SEDF for short)of G if f[e]=f(N[e])=Σ_( e′∈N[e])f(e′)≥1,for every edge e∈E(G).w(f)=Σe∈E f(e)is called the weight of f.The signed edge dom...A function f:E(G)→{−1,1}is called a signed edge dominating function(SEDF for short)of G if f[e]=f(N[e])=Σ_( e′∈N[e])f(e′)≥1,for every edge e∈E(G).w(f)=Σe∈E f(e)is called the weight of f.The signed edge domination numberγs′(G)of G is the minimum weight among all signed edge dominating functions of G.In this paper,we initiate the study of this parameter for G a complete multipartite graph.We provide the lower and upper bounds ofγs′(G)for G a complete r-partite graph with r even and all parts equal.展开更多
Let G=(V, E) be a simple graph without an isolate. A subset T of V is a total dominating set of G if for any there exists at least one vertex such that .The total domination number γ1(G) of G is the minimum order of ...Let G=(V, E) be a simple graph without an isolate. A subset T of V is a total dominating set of G if for any there exists at least one vertex such that .The total domination number γ1(G) of G is the minimum order of a total dominating set of G. This paper proves that if G is a connected graph with n≥3 vertices and minimum degree at least two.展开更多
A path π = [v1, v2, …, vk] in a graph G = (V, E) is an uphill path if deg(vi) ≤ deg(vi+1) for every 1 ≤ i ≤ k. A subset S ⊆ V(G) is an uphill dominating set if every vertex vi ∈ V(G) lies...A path π = [v1, v2, …, vk] in a graph G = (V, E) is an uphill path if deg(vi) ≤ deg(vi+1) for every 1 ≤ i ≤ k. A subset S ⊆ V(G) is an uphill dominating set if every vertex vi ∈ V(G) lies on an uphill path originating from some vertex in S. The uphill domination number of G is denoted by γup(G) and is the minimum cardinality of the uphill dominating set of G. In this paper, we introduce the uphill domination polynomial of a graph G. The uphill domination polynomial of a graph G of n vertices is the polynomial , where up(G, i) is the number of uphill dominating sets of size i in G, and γup(G) is the uphill domination number of G, we compute the uphill domination polynomial and its roots for some families of standard graphs. Also, UP(G, x) for some graph operations is obtained.展开更多
A signed(res. signed total) Roman dominating function, SRDF(res.STRDF) for short, of a graph G =(V, E) is a function f : V → {-1, 1, 2} satisfying the conditions that(i)∑v∈N[v]f(v) ≥ 1(res.∑v∈N(v)f(v) ≥ 1) for ...A signed(res. signed total) Roman dominating function, SRDF(res.STRDF) for short, of a graph G =(V, E) is a function f : V → {-1, 1, 2} satisfying the conditions that(i)∑v∈N[v]f(v) ≥ 1(res.∑v∈N(v)f(v) ≥ 1) for any v ∈ V, where N [v] is the closed neighborhood and N(v) is the neighborhood of v, and(ii) every vertex v for which f(v) =-1 is adjacent to a vertex u for which f(u) = 2. The weight of a SRDF(res. STRDF) is the sum of its function values over all vertices.The signed(res. signed total) Roman domination number of G is the minimum weight among all signed(res. signed total) Roman dominating functions of G. In this paper,we compute the exact values of the signed(res. signed total) Roman domination numbers of complete bipartite graphs and wheels.展开更多
Let G = (V,E) be a simple graph. For any real function g : V →R and a subset S 包涵于V, we write g(S) = ∑v∈sg(v). A function f : V → [0,1] is said to be a fractional dominating function (FDF) of G if f(...Let G = (V,E) be a simple graph. For any real function g : V →R and a subset S 包涵于V, we write g(S) = ∑v∈sg(v). A function f : V → [0,1] is said to be a fractional dominating function (FDF) of G if f(N[v]) ≥ 1 holds for every vertex v ∈ V(G). The fractional domination number γf(G) of G is defined as γf(G) = min{f(V)|f is an FDF of G }. The fractional total dominating function f is defined just as the fractional dominating function, the difference being that f(N(v)) ≥ 1 instead of f(N[v])≥ 1. The fractional total domination number γ^0f(G) of G is analogous. In this note we give the exact values of γf(Cm× Pn) and γ^0f(Cm × Pn) for all integers m ≥ 3 and n ≥ 2.展开更多
A function f: V( G)→{1,1} defined on the vertices of a graph G is a signed total dominating function (STDF) if the sum of its function values over any open neighborhood is at least one. An STDF f is minimal if t...A function f: V( G)→{1,1} defined on the vertices of a graph G is a signed total dominating function (STDF) if the sum of its function values over any open neighborhood is at least one. An STDF f is minimal if there does not extst a STDF g: V(G)→{-1,1}, f≠g, for which g ( v )≤f( v ) for every v∈V( G ). The weight of a STDF is the sum of its function values over all vertices. The signed total domination number of G is the minimum weight of a STDF of G, while the upper signed domination number of G is the maximum weight of a minimal STDF of G, In this paper, we present sharp upper bounds on the upper signed total domination number of a nearly regular graph.展开更多
Let γ f(G) and γ~t f(G) be the fractional domination number and fractional total domination number of a graph G respectively. Hare and Stewart gave some exact fractional domination number of P n×P m (grid graph...Let γ f(G) and γ~t f(G) be the fractional domination number and fractional total domination number of a graph G respectively. Hare and Stewart gave some exact fractional domination number of P n×P m (grid graph) with small n and m . But for large n and m , it is difficult to decide the exact fractional domination number. Motivated by this, nearly sharp upper and lower bounds are given to the fractional domination number of grid graphs. Furthermore, upper and lower bounds on the fractional total domination number of strong direct product of graphs are given.展开更多
In this article, we consider the continuous gas in a bounded domain ∧ of R^+ or R^d described by a Gibbsian probability measure μη∧ associated with a pair interaction φ, the inverse temperature β, the activity...In this article, we consider the continuous gas in a bounded domain ∧ of R^+ or R^d described by a Gibbsian probability measure μη∧ associated with a pair interaction φ, the inverse temperature β, the activity z 〉 0, and the boundary condition η. Define F ∫ωf(s)wA(ds). Applying the generalized Ito's formula for forward-backward martingales (see Klein et M. [5]), we obtain convex concentration inequalities for F with respect to the Gibbs measure μη∧. On the other hand, by FKG inequality on the Poisson space, we also give a new simple argument for the stochastic domination for the Gibbs measure.展开更多
The domination problem of graphs is an important issue in the field of graph theory.This paper mainly considers the Italian domination number of the strong product between two paths.By constructing recursive Italian d...The domination problem of graphs is an important issue in the field of graph theory.This paper mainly considers the Italian domination number of the strong product between two paths.By constructing recursive Italian dominating functions,the upper bound of its Italian domination number is obtained,and then a partition method is proposed to prove its lower bound.Finally,this paper yields a sharp bound for the Italian domination number of the strong product of paths.展开更多
Let be a graph. A function is said to be a Signed Dominating Function (SDF) if holds for all . The signed domination number . In this paper, we determine the exact value of the Signed Domination Number of graphs and f...Let be a graph. A function is said to be a Signed Dominating Function (SDF) if holds for all . The signed domination number . In this paper, we determine the exact value of the Signed Domination Number of graphs and for , which is generalized the known results, respectively, where and are denotes the k-th power graphs of cycle and path .展开更多
Let G be a simple graph with no isolated vertices. A set S of vertices of G is a total dominating set if every vertex of G is adjacent to some vertex in S . The total domination number of G , denoted by γ t (G) , is ...Let G be a simple graph with no isolated vertices. A set S of vertices of G is a total dominating set if every vertex of G is adjacent to some vertex in S . The total domination number of G , denoted by γ t (G) , is the minimum cardinality of a total dominating set of G . It is shown that if G is a graph of order n with minimum degree at least 3, then γ t (G)≤n/2 . Thus a conjecture of Favaron, Henning, Mynhart and Puech is settled in the affirmative.展开更多
Let G=(V,E) be a simple graph. For any real valued function f∶V→R and SV, let f(S)=∑ u∈S?f(u). A majority dominating function is a function f∶V→{-1,1} such that f(N)≥1 for at least half the vertices v∈V. Then ...Let G=(V,E) be a simple graph. For any real valued function f∶V→R and SV, let f(S)=∑ u∈S?f(u). A majority dominating function is a function f∶V→{-1,1} such that f(N)≥1 for at least half the vertices v∈V. Then majority domination number of a graph G is γ maj(G)=min{f(V)|f is a majority dominating function on G}. We obtain lower bounds on this parameter and generalize some results of Henning.展开更多
Let G=(V,E) be a simple graph. For any real valued function f:V →R, the weight of f is f(V) = ∑f(v) over all vertices v∈V . A signed total dominating function is a function f:V→{-1,1} such that f(N(v)) ≥1 for...Let G=(V,E) be a simple graph. For any real valued function f:V →R, the weight of f is f(V) = ∑f(v) over all vertices v∈V . A signed total dominating function is a function f:V→{-1,1} such that f(N(v)) ≥1 for every vertex v∈V . The signed total domination number of a graph G equals the minimum weight of a signed total dominating function on G . In this paper, some properties of the signed total domination number of a graph G are discussed.展开更多
摘要The closure of Gdenoted by cl(G),is obtained by recursively performing the local completion operation at eligible vertices as long as possible.The core of H is the graph co(H)obtained from H by deleting all the vertices of degree 1,and replacing the path xyz by the edge xz for each y of degree 2.In this paper,we discuss the Hamiltonicity of 3-connected claw-free graph under domination number and clique covering,and the Hamiltonicity of the 3-connected claw-free and hourglass-free graphs under domination number.We show that:(1)G is hamiltonian or cl(G)=L(H),and co(H)can be contracted to the Petersen graph if G is a 3-connected claw-free graph and thedomination number ofG is at most 6;(2)G is hamiltonian or cl(G)=L(H),where the reduction ofco(H)is a member of{P,P(14)},if G is a 3-connected claw-free,hourglass-free graph with domination number at most 11;(3)G is hamiltonian or cl(G)=L(H),and co(H)can becontracted to the Petersen graph,if G is a 3-connected claw-free graph with clique covering number at most 12.
摘要Outer-independent Roman domination on graphs originates from the defensive strategy of Ancient Rome,which is that if any city without an army is attacked,a neighboring city with two armies could mobilize an army to support it and any two cities that have no army cannot be adjacent.The outer-independent Roman domination on graphs is an attractive topic in graph theory,and the definition is described as follows.Given a graph G=(V,E),a function f:V(G)→{0,1,2}is an outer-independent Roman dominating function(OIRDF)if f satisfies that every vertex v∈V with f(v)=0 has at least one adjacent vertex u∈N(v)with f(u)=2,where N(v)is the open neighborhood of v,and the set V0={v|f(v)=0}is an independent set.The weight of an OIRDF f is w(f)=∑v∈Vf(v).The value of minf w(f)is the outerindependent Roman domination number of G,denoted asγoiR(G).This paper is devoted to the study of the outer-independent Roman domination number of the Cartesian product of paths Pn□Pm.With the help of computer,we find some recursive OIRDFs and then we present an upper bound ofγoiR(Pn□Pm).Furthermore,we prove the lower bound ofγoiR(Pn□Pm)(n≤3)is equal to the upper bound.Hence,we achieve the exact value ofγoiR(Pn□Pm)for n≤3 and the upper bound ofγoiR(Pn□Pm)for n≥4.
基金Supported by the National Natural Science Foundation Youth Fund of China(Grant No.11701059)The Chongqing Natural Science Foundation Innovation and Development Joint Fund(Municipal Education Commission)(Grant No.CSTB2022NSCQ-LZX0003)The Open Research Fund of Key Laboratory of Nonlinear Analysis&Applications(Central China Normal University),Ministry of Education,P.R.China。
摘要Consider a graph G=(V,E).A perfect double Roman dominating function(PDRDF for short)is a function h:V→{0,1,2,3}that satisfies the condition∑y∈NG[x],h(y≥1)h(y)=|{y∈NG(x):h(y)≥1}|+2 for any x∈V with h(x)≤1.The weightω(h)of this function is∑y∈Vh(y).The perfect double Roman domination number(PDRD-number)of G,denoted byγdRp(G),is defined as the minimum weight among all PDRDFs of G.This article presents a comprehensive analysis of the PDRD-number of connected cographs,demonstrating that it falls within the set{2,3,4,5,6}.Furthermore,it establishes that for any integer i≥7,there is a connected cograph G such that its PDRD-number is equal to i.
摘要LetΩbe homogeneous of degree zero,integrable on Sd−1 and have vanishing moment of order one,a be a function on Rd such that ∇a∈L∞(Rd).Let T*Ω,a be the maximaloperator associated with the d-dimensional Calder´on commutator defined by T*Ωaf(x):=supε>0|∫|x-y|>ε^Ω(x-y)/|x-y|d+1(a(x)-a(y))f(y)dy.In this paper,the authors establish bilinear sparse domination for T*Ω,a under the assumption Ω∈L∞(Sd−1).As applications,some quantitative weighted bounds for T*Ω,a are obtained.
基金supported in part by the National Natural Science Foundation of China(U20A2068)Zhejiang Provincial Natural Science Foundation of China(LD19A010001,LZ24F030009).
摘要The Roman domination problem is an important combinatorial optimization problem that is derived from an old story of defending the Roman Empire and now regains new significance in cyber space security,considering backups in the face of a dynamic network security requirement.In this paper,firstly,we propose a Roman domination game(RDG)and prove that every Nash equilibrium(NE)of the game corresponds to a strong minimal Roman dominating function(S-RDF),as well as a Pareto-optimal solution.Secondly,we show that RDG is an exact potential game,which guarantees the existence of an NE.Thirdly,we design a game-based synchronous algorithm(GSA),which can be implemented distributively and converge to an NE in O(n)rounds,where n is the number of vertices.In GSA,all players make decisions depending on local information.Furthermore,we enhance GSA to be enhanced GSA(EGSA),which converges to a better NE in O(n2)rounds.Finally,we present numerical simulations to demonstrate that EGSA can obtain a better approximate solution in promising computation time compared with state-of-the-art algorithms.
摘要A dominating set D in a graph G is called an injective equitable dominating set (Inj-equitable dominating set) if for every , there exists such that u is adjacent to v and . The minimum cardinality of such a dominating set is denoted by and is called the Inj-equitable domination number of G. In this paper, we introduce the injective equitable domination of a graph and study its relation with other domination parameters. The minimal injective equitable dominating set, the injective equitable independence number , and the injective equitable domatic number are defined.
基金Supported by the National Natural Science Foundation of China (Grant No. 71774078)。
摘要A function f:E(G)→{−1,1}is called a signed edge dominating function(SEDF for short)of G if f[e]=f(N[e])=Σ_( e′∈N[e])f(e′)≥1,for every edge e∈E(G).w(f)=Σe∈E f(e)is called the weight of f.The signed edge domination numberγs′(G)of G is the minimum weight among all signed edge dominating functions of G.In this paper,we initiate the study of this parameter for G a complete multipartite graph.We provide the lower and upper bounds ofγs′(G)for G a complete r-partite graph with r even and all parts equal.
摘要Let G=(V, E) be a simple graph without an isolate. A subset T of V is a total dominating set of G if for any there exists at least one vertex such that .The total domination number γ1(G) of G is the minimum order of a total dominating set of G. This paper proves that if G is a connected graph with n≥3 vertices and minimum degree at least two.
摘要A path π = [v1, v2, …, vk] in a graph G = (V, E) is an uphill path if deg(vi) ≤ deg(vi+1) for every 1 ≤ i ≤ k. A subset S ⊆ V(G) is an uphill dominating set if every vertex vi ∈ V(G) lies on an uphill path originating from some vertex in S. The uphill domination number of G is denoted by γup(G) and is the minimum cardinality of the uphill dominating set of G. In this paper, we introduce the uphill domination polynomial of a graph G. The uphill domination polynomial of a graph G of n vertices is the polynomial , where up(G, i) is the number of uphill dominating sets of size i in G, and γup(G) is the uphill domination number of G, we compute the uphill domination polynomial and its roots for some families of standard graphs. Also, UP(G, x) for some graph operations is obtained.
基金The NSF(11271365)of Chinathe NSF(BK20151117)of Jiangsu Province
摘要A signed(res. signed total) Roman dominating function, SRDF(res.STRDF) for short, of a graph G =(V, E) is a function f : V → {-1, 1, 2} satisfying the conditions that(i)∑v∈N[v]f(v) ≥ 1(res.∑v∈N(v)f(v) ≥ 1) for any v ∈ V, where N [v] is the closed neighborhood and N(v) is the neighborhood of v, and(ii) every vertex v for which f(v) =-1 is adjacent to a vertex u for which f(u) = 2. The weight of a SRDF(res. STRDF) is the sum of its function values over all vertices.The signed(res. signed total) Roman domination number of G is the minimum weight among all signed(res. signed total) Roman dominating functions of G. In this paper,we compute the exact values of the signed(res. signed total) Roman domination numbers of complete bipartite graphs and wheels.
基金Supported by the National Natural Science Foundation of China(Grant Nos.1136102411061014)the Jiangxi Provincial Science and Technology Project(Grant No.KJLD12067)
摘要Let G = (V,E) be a simple graph. For any real function g : V →R and a subset S 包涵于V, we write g(S) = ∑v∈sg(v). A function f : V → [0,1] is said to be a fractional dominating function (FDF) of G if f(N[v]) ≥ 1 holds for every vertex v ∈ V(G). The fractional domination number γf(G) of G is defined as γf(G) = min{f(V)|f is an FDF of G }. The fractional total dominating function f is defined just as the fractional dominating function, the difference being that f(N(v)) ≥ 1 instead of f(N[v])≥ 1. The fractional total domination number γ^0f(G) of G is analogous. In this note we give the exact values of γf(Cm× Pn) and γ^0f(Cm × Pn) for all integers m ≥ 3 and n ≥ 2.
摘要A function f: V( G)→{1,1} defined on the vertices of a graph G is a signed total dominating function (STDF) if the sum of its function values over any open neighborhood is at least one. An STDF f is minimal if there does not extst a STDF g: V(G)→{-1,1}, f≠g, for which g ( v )≤f( v ) for every v∈V( G ). The weight of a STDF is the sum of its function values over all vertices. The signed total domination number of G is the minimum weight of a STDF of G, while the upper signed domination number of G is the maximum weight of a minimal STDF of G, In this paper, we present sharp upper bounds on the upper signed total domination number of a nearly regular graph.
摘要Let γ f(G) and γ~t f(G) be the fractional domination number and fractional total domination number of a graph G respectively. Hare and Stewart gave some exact fractional domination number of P n×P m (grid graph) with small n and m . But for large n and m , it is difficult to decide the exact fractional domination number. Motivated by this, nearly sharp upper and lower bounds are given to the fractional domination number of grid graphs. Furthermore, upper and lower bounds on the fractional total domination number of strong direct product of graphs are given.
摘要In this article, we consider the continuous gas in a bounded domain ∧ of R^+ or R^d described by a Gibbsian probability measure μη∧ associated with a pair interaction φ, the inverse temperature β, the activity z 〉 0, and the boundary condition η. Define F ∫ωf(s)wA(ds). Applying the generalized Ito's formula for forward-backward martingales (see Klein et M. [5]), we obtain convex concentration inequalities for F with respect to the Gibbs measure μη∧. On the other hand, by FKG inequality on the Poisson space, we also give a new simple argument for the stochastic domination for the Gibbs measure.
基金Supported by the National Natural Science Foundation of China(Grant No.11551002)The Natural Science Foundation of Qinghai Province(Grant No.2019-ZJ-7093).
摘要The domination problem of graphs is an important issue in the field of graph theory.This paper mainly considers the Italian domination number of the strong product between two paths.By constructing recursive Italian dominating functions,the upper bound of its Italian domination number is obtained,and then a partition method is proposed to prove its lower bound.Finally,this paper yields a sharp bound for the Italian domination number of the strong product of paths.
摘要Let be a graph. A function is said to be a Signed Dominating Function (SDF) if holds for all . The signed domination number . In this paper, we determine the exact value of the Signed Domination Number of graphs and for , which is generalized the known results, respectively, where and are denotes the k-th power graphs of cycle and path .
摘要Let G be a simple graph with no isolated vertices. A set S of vertices of G is a total dominating set if every vertex of G is adjacent to some vertex in S . The total domination number of G , denoted by γ t (G) , is the minimum cardinality of a total dominating set of G . It is shown that if G is a graph of order n with minimum degree at least 3, then γ t (G)≤n/2 . Thus a conjecture of Favaron, Henning, Mynhart and Puech is settled in the affirmative.
摘要Let G=(V,E) be a simple graph. For any real valued function f∶V→R and SV, let f(S)=∑ u∈S?f(u). A majority dominating function is a function f∶V→{-1,1} such that f(N)≥1 for at least half the vertices v∈V. Then majority domination number of a graph G is γ maj(G)=min{f(V)|f is a majority dominating function on G}. We obtain lower bounds on this parameter and generalize some results of Henning.
摘要Let G=(V,E) be a simple graph. For any real valued function f:V →R, the weight of f is f(V) = ∑f(v) over all vertices v∈V . A signed total dominating function is a function f:V→{-1,1} such that f(N(v)) ≥1 for every vertex v∈V . The signed total domination number of a graph G equals the minimum weight of a signed total dominating function on G . In this paper, some properties of the signed total domination number of a graph G are discussed.