Title Author(s) Citation Issue Date URL MINIMUM OF POSITIVE DEFINITE QUADRATIC FORMS(Analytic Number Theory) KITAOKA, YOSHIYUKI 数理解析研究所講究録 (1996), 958: 105-110 1996-08 http://hdl.handle.net/2433/60458 Right Type Textversion Departmental Bulletin Paper publisher Kyoto University 数理解析研究所講究録 958 巻 1996 年 105-110 105 MINIMUM OF POSITIVE DEFINITE QUADRATIC FORMS YOSHIYUKI KITAOKA(北岡良之) Department of Mathematics, School of Science Nagoya University $(k\delta\prime z\mathrm{x}\tau \mathrm{E})$ We are concerned with reresentation of positive definite quadratic forms by a positive definite quadra,tic form. Let us consider the following assertion , : Let $M,$ $N$ be positi $ve$ definite adra $tic$ la ttices over with rank a $n\mathrm{d}rank(N)=n$ respectively. We that the localiz a is repre, for every prime , th at is the is an isom etry from to . Then there exis a constant dependent only on $N$ so that $M$ is represented $b.vN$ if $\min(M)>c(N)$ , where nuin $(M)$ denotes positive number represen le by $M$ . We know that the assertion is true if $n\geq 2m+3$ a.nd there are several results. But, the present problem is whether the condition $7l\geq 2m+3$ is the best possible or . It is known that this is best if $rn=1$ , that is is false. But in the case of we know at present, is is false if . We do not know anything the case of $n-m=4$ . Anywav, analyzing the counter-example, we come to the fullowing two assertions and . : There exists a. const ant dependent only on $N$ so that $llI$ is resen $tedb.\}^{f}N$ if $\min(N)>c’(N)$ a.nd is represented by for every $(M)=?\uparrow\iota$ $\mathrm{Z}$ $\mathrm{A}_{1n,n}$ $q\mathrm{u}$ $\mathrm{a}ss\mathrm{u}me$ $N_{\mathrm{p}}$ $p$ $\mathrm{s}e\mathrm{n}tedb.\gamma$ $t\mathrm{i}o\mathrm{J}’ M_{\mathrm{p}}$ $\mathrm{r}e$ $N_{p}$ $ll/I_{\mathrm{p}}$ $t\epsilon$ $\mathrm{c}(N)$ $tl_{l}e$ $t_{\sim}\rho d$ $a,\sim \mathrm{s}t$ $\mathrm{A}_{m,n}$ $\mathrm{t}1^{-}1\mathrm{e}$ $\mathrm{n}\mathrm{o}1_{}$ $\mathrm{A}_{1,4}$ $\mathrm{w}\mathrm{h}\mathrm{a}\mathrm{t}_{\iota}$ $m\geq\tau_{)}\sim,$ $\mathrm{t}\mathrm{h}\mathrm{a}\dagger,$ $n-m\underline{<_{\backslash }}3$ $\mathrm{A}_{t)}\iota,n$ $\mathrm{i}\mathrm{I}1$ $\mathrm{A}\mathrm{P}\mathrm{W}_{m,n}$ $\mathrm{A}\mathrm{P}\mathrm{W}_{m,n}$ $\mathrm{R}_{m,n}$ $c’(l\backslash ^{\tau}’)$ $T^{\rho}arrow p-$ $M_{p}$ $p\mathrm{r}i_{I}\mathrm{n}e_{I)}$ $pril\mathit{1}\mathit{1}iti\mathrm{v}\rho.\iota_{\mathrm{J}^{\gamma}}$ $N_{\mathrm{p}}$ . : There is a lattice cont such th at is primiti rep.r.esented by prime and $\min(’M’)$ is still large if $\min(M)$ is 1 arge. for If the assertion is true, then the assertion is reduced to the apparently weaker assertion . If the assertion is false, it becomes possible to make a counter-example to the assertion . matter of fact, is true but is false, and it yields examples of $N$ such that is false. Anywa it is important to study the behaviour of the minimum of quardatic la.ttices when we vary thenl. Our aim is to show $M^{l}$ $\mathrm{R}_{m,n}$ $N_{p}$ $e\mathrm{v}er\mathrm{J}^{f}$ $\mathrm{a}i\mathrm{n}ingM$ $\mathit{1}VI_{\mathrm{P}}^{;}$ $p$ $\mathrm{R}_{m,n}$ $\mathrm{A}\mathrm{P}\mathrm{W}_{m,n}$ $\mathrm{A}_{m,n}$ $\mathrm{t}_{}1_{1}\mathrm{e}\mathrm{n}$ $\mathrm{R}_{m,n}$ $\mathrm{A}_{?7,n},$ $\mathrm{R}_{1,4}$ $\mathrm{A}\circ,$ , $\mathrm{a}$ $\Lambda_{1,4}$ $‘ \mathrm{y}$ $\mathrm{V}^{\rho}ly$ $\mathrm{A}\mathrm{P}\mathrm{W}_{1,4}$ 106 Theorem. The assertion $\mathrm{R}_{m,n}$ is true if $n-m>3,$ $?7,$ or $n=2\uparrow n\geq 12$ . $\geq 2m+1$ is false, we can construct a counter-example to the asRemark. If the assertion , as above. When the case of $n<2\prime n$ seeIns to have a different nature fronu sertion the case of $n\geq 2m$ . $\mathrm{R}_{n,n}$ $\mathrm{A}_{m,n}$ To prove , we are involved in analytic nulnber theory. The rest is a brief sumnlary of the proof. field of rational numbers the ring of integers, and We denote by and their p–adic comple,tions. Terminology and notation on qua.dratic forms are those scale $s(M)$ deover on a quadratic space from [K]. For a lattice on denotes a -module spanned by notes $\{B(x, y)|x, y\in\Lambda f\}$ , and the norm denote it is similarly defined. $dM,$ $\{Q(X)|x\in M\}$ . Even for the localization respectively. A positive lattice means a lattice on a positive of $M,$ the definite quadratic space over Q. We give proofs only for a few assertions. $\mathrm{i}\dagger‘$ $\mathfrak{t}_{\mathrm{L}}\mathrm{h}\mathrm{e}$ $\mathrm{Z},$ $\mathrm{Q},$ $\mathrm{Q}_{p}$ $\mathrm{Z}_{\mathrm{p}}$ $V$ $\mathrm{A}l$ $\mathrm{Q},$ $n(\Lambda I)$ $\mathrm{t}\mathrm{l}\mathrm{l}\mathrm{e}$ $\mathrm{Z}$ $d\Lambda I_{\mathrm{p}}$ $ll,f_{\mathrm{p}}$ $\mathrm{d}\mathrm{i}_{\mathrm{S}\mathrm{C}\mathrm{r}}\mathrm{i}\mathrm{m}\mathrm{i}\mathrm{n}\mathrm{a}11\mathrm{t}$ Definition. $M_{\mathrm{p}}$ For a real number , we define the decimal part $x$ $-1/2\leq\lceil x\rceil<1/2$ Note that Definition. $\lceil_{\backslash }\prime r1^{2}=\lceil-’.t1^{2}$ and $\lceil x\rceil$ $x-\lceil x,\rceil\in \mathrm{Z}$ by the conditions . for every real number . $x$ For positive numbers $a,$ $b$ , we write $a\ll_{m}b$ such that $a/b<c$ . If both $a\ll_{m}b$ , we say that a positive definite matrix $S^{(m)}=$ if there is a positive number dependent only on hold, then we write $c$ $\mathrm{a}\mathrm{l}\iota \mathrm{d}l)\ll_{m}$ $a$ $a_{\wedge m}^{\vee}b$ If $m$ is $\mathrm{a}1$ ) Definition. $(s_{\mathrm{s},\mathrm{j}})$ is $m$ absolute constant, then we omit numbers -diagonal if we have For $(c_{1}, c_{2})$ $\mathrm{p}\mathrm{o}\mathrm{S}\mathrm{i}\mathrm{t}\mathrm{i}_{\mathrm{V}\mathrm{P}}$ $c_{1},$ $c_{2}$ $m$ . . $\mathrm{c}_{1}\mathrm{d}\mathrm{i}\mathrm{a}\mathrm{g}(s1,1, \cdots, s_{m,m})<S<c_{2}\mathrm{d}\mathrm{i}\mathrm{a}\mathrm{g}(s1,1, \cdots, s_{m,m})$ If is in the Siegel donlain , then there exist positive nunibers -diagonal (see Ch.2 in [K]). so that is $S$ $\mathfrak{S}$ $S$ $(C_{1}{}_{)}C_{2})$ $c_{1},$ . $c_{2}$ dependent on $\mathfrak{S}$ 107 Lerrlma 1. -diagonal. For a have $L\cdot et,$ $M=\mathrm{Z}[v_{1}, \cdots, v_{m}]$ $(c_{1}, c_{2})$ be a positi $ve$ lattice and assume that in $M$ and for a natural $(B(v_{i}, v_{\mathrm{j}}))$ $\mathit{1}\mathrm{J}\mathrm{r}imiti\mathrm{V}\mathrm{e}el\mathrm{e}\mathrm{m}e\mathrm{n}tw=\sum_{i=1}^{1n}r_{i}v_{i}$ is $nu\mathrm{m}be\mathrm{r}$ $N_{\mathit{1}}\mathfrak{s}\mathrm{v}e$ $1 \mathrm{n}\mathrm{i}\mathfrak{n}(M+\mathrm{Z}[(\{)/N1)_{\wedge c}^{\vee}1,c_{2}\mathrm{n}?\mathrm{i}\mathrm{n}(\mathrm{n}\mathrm{l}\mathrm{i}\mathrm{n}(M),\min\sum_{=}^{m}b\in \mathrm{Z},N\{bi1\lceil br_{i}/N\rceil^{2}q(v_{i})l\cdot$ Proof. Since there are positive constants $c_{1}. $C_{1}{}_{)}C_{2}$ so $\mathrm{t}\mathrm{h}\mathrm{a},\mathrm{t}$ \sum_{1=1}^{m}x_{i}Q2(vi)<Q(\sum^{m}x_{i}v,))<C_{2}i=1\dot{\mathrm{z}}\sum_{=1}^{m}X^{2}iQ(vi)$ , putting $:= \sum_{=i1}^{m}xiQ2(\prime vi)$ $Q^{\iota}( \sum_{i=1}^{m}xivi)$ , we have $\min_{Q}(M+\mathrm{Z}[w/N])_{\wedge Q}^{\vee}1,\mathrm{c}2(\min_{Q’}M+\mathrm{Z}[u’/N])$ $= \min(’\sum_{i=1}^{n}(bi+br_{i}/N)^{2}Q(vt))$ where integers $b_{i}(^{}i=1, \cdots, m)$ should satisfy under restriction $N|b$ , the lninimunl is yields for some , it is equal to $b,$ $\mathrm{f},1\mathrm{l}\mathrm{a}.\mathrm{t}$ $\mathrm{t}1_{1}\mathrm{e}$ ) $\mathrm{t}+br_{i}/N\neq $l$ $b_{i}+br_{\mathrm{I}}/N\neq()$ $\min(l\downarrow I)$ \mathrm{t}\mathrm{J}$ , and $\Lambda f$ $\Lambda,I’\supset l1I$ $\mathrm{J}l’$ be positive lattices of rank be positive numbers] and a natu number. we have $tq_{1_{\rangle}}\cdots,$ $\gamma N$ If $i$ $b$ $\mathrm{t}1\overline{1}\mathrm{a}\mathfrak{t}_{}\mathrm{t}1^{-}1\mathrm{e}$ $q_{i}$ $r_{1},$ $r\mathrm{a}\mathit{1}$ . $\square$ $M=\mathrm{r}\mathrm{a}\mathrm{n}\mathrm{k}l|p’$ $\min(M’)\leq 1\mathrm{n}\mathrm{i}\mathrm{n}(M)\leq[M’ : \mathrm{J}/f]^{2}\min(M’)$ Theorem 1. Le $r_{1}=1$ , and finall. for some . By noting condition $N$ \dag er $\prime i$ $\min(\min(M),\min\sum_{=}^{m}b\in \mathrm{Z}|N\{bi1\lceil br_{t}/N1^{2}Q(vi))$ Remark. Let and implies , . Then the condition . $\cdots,$ $r_{\mathit{5}}$ non-ze $ro$ integers $Th\mathrm{P}l1$ ) $:=b \in \mathrm{Z}N;1\mathrm{J}1\mathrm{i}|\mathrm{n}b(_{j}\sum_{=1}^{i}\lceil br_{j}/\mathit{1}\mathrm{V}1\wedge)’$ $qj$ $\geq\min((\frac{r_{1}}{2r_{2}})^{2}q_{1},$ $\cdots,$ $( \frac{r_{i-1}}{2r_{l}})^{2}q_{i-1},$ $N-2 \sum^{t}rj=1\mathrm{i}^{q}j)2$ . $\dagger 1^{\gamma}i\mathrm{t}\cdot h$ 108 Proof. Suppose that (1) $K \leq(\frac{r_{j}}{2r_{j+1}})^{2}q_{i}$ is attained We will show that $K$ and $|b|\leq N/2$ . The condition $I\backslash ^{\Gamma}$ (2) for $j=1,$ $\cdot 4\cdot,$ $t-\perp$ . Suppose t,hat an integer give the mininuum implies $b\neq()$ . First, we claim a,t $b=1$ . $N\{b$ $|br_{j}|\leq N/2$ $b$ for $j=\perp,$ $\cdots,$ $t$ . it is true because of $r_{1}=1$ . Suppose that (2) is true for $j=i$ ; then we llave $|br_{i}|\leq N/2$ and hence . , which yields Now using (1), we $N/2$ . Thus (2) has been shown inductively. and then The condition (2) implies When $j=1_{\tau}$ $|b|\leq\sqrt{I\mathrm{f}/q_{i}}N/|r,$ $I\iota’\geq\lceil br_{\dot{\mathrm{t}}}/N\rceil^{2}q_{t}=(br_{\mathrm{i}}/N)^{2}qi$ $|$ $1\mathrm{l}\mathrm{a}\mathrm{v}\mathrm{e}|br_{i+1}|\underline{<’.}\sqrt{J\mathrm{t}’/q;}\cdot N/|r_{i}|\cdot|r_{\mathrm{a}+1}|\leq|r_{i}|/(2|r_{t+}1|)\cdot N/|r_{i}|\cdot|?_{t}+1|=$ $\lceil br_{\mathrm{j}}/N\rceil^{2}=(br_{j}/N)^{2}$ $I \mathrm{i}’=\sum_{j=1}^{i}(brj/N)^{2}qj=b^{2}/N^{2}\sum^{1}rjqjj=12\geq N^{-2}\sum_{=j1}^{9}rj2q_{j}$ This completes the proof. Corollary 1. Suppose $I\zeta\gg\sqrt{q_{1}q_{2}}/N$ Corollary 2. Let if $q_{j},$ $\square$ $t=2$ . $Th\rho n$ we have $r_{2}^{2}\wedge\vee\sqrt{q_{1}/q_{\sim^{\supset}}}N$ $r_{j},$ $t,$ . $N,$ $K$ be th or if both $\mathrm{o}se$ $(r_{2}, N)=1$ and $\sqrt{q_{1}/q_{2}}N\ll 1$ in Theorem 1, and put $\Delta:=\mathrm{I}^{t}\mathrm{I}q_{k},$ $\eta_{j}:=\frac{|r_{j}|}{N^{(\mathrm{j}1})/t\Delta_{j^{\prime 2}}1}k=1kj$ $\Delta_{j}:=\Delta^{-(}i-1)/i\mathrm{I}_{<}\mathrm{I}^{q}k,$ for $j=1,$ $\cdots,$ $t$ . $\mathrm{T}l_{l}eD\mathrm{v}veha\mathrm{b}’\underline{\theta}$ (i) 4 ( $\frac{\Delta}{N^{2}})^{-1/i}I_{\mathrm{L}}’$ $\geq \mathrm{l}\mathrm{n}\mathrm{i}\mathrm{n}((\eta_{1}/\eta_{2})2,$ $\cdots,$ $( \eta_{t-1}/\eta‘)2,\sum_{j=1}^{i}\eta_{\mathrm{j}}^{2}(\Delta/N2)^{1}-j/t(\mathrm{I}_{k}\mathrm{I}j<\leq iq_{k}1^{-},1)$ $\geq\min((\eta_{1}/\eta_{2})^{2}, \cdots, (\eta_{i1}-/\eta_{t})2\eta_{t}:)2$ (ii) $\eta_{1}=1$ , (iii) if $q_{1}\geq q_{2}\geq\cdots\geq q_{i}$ To undestand $I\backslash ^{r}$ , then we $h\mathrm{a}\mathrm{V}^{\rho}\Delta_{j}\geq 1$ for $j=1,$ $\cdots$ , it is better to give an estimate from above. , . $t$ . 109 Proposition 1. Let $N$ a natural er with $q_{1},$ nu.m be positive numbers, and $(r_{1}, \cdots, r_{t}, N)=1$ . Put , $\cdots$ $\mathrm{b}$ $q_{l}$ $\Delta=\prod_{i=1}^{t}q_{i}$ $i\mathrm{I}^{\urcorner}he\mathrm{n}$ we have $\mathrm{t}f,\mathrm{e}$ , $r_{i}$ $\cdots,$ $I \mathrm{f}:=\min_{b\in \mathrm{Z},N\dagger b}(\sum_{\mathrm{j}=1}^{i}\lceil br_{\mathrm{j}}/N\rceil^{2}qJ’)\backslash$ integers, and finall. $\gamma$ . follo wing: (1) $I\mathrm{f}\geq \mathrm{m}\vec{\mathrm{l}}\mathrm{n}\{q_{1}, \cdots, q_{i}\}$ (2) $r\mathrm{l},$ if $K/\leq_{i}(\Delta/N^{2})^{1}/i$ or $I\backslash ^{r}\ll \mathrm{s}(\Delta/N^{2})^{1/9}$ $( \Delta/N^{2})^{1/9}\ll_{t}\min\{q_{1}, \cdots, q_{i}\}$ . We must study the distribution of isotropic vectors in a quadratic space over a finite prime field to take account of the condition at a finite prime in the assertion . For an odd prinle denotes the prime field with elements. $\mathrm{R}_{n.’ $\mathrm{P},$ $p$ $F_{\mathrm{p}}$ Lemlna 2. Let $V=F_{p}[e_{1}, e_{2}]$ be a regular quadratic space over the field . quadra $tic$. form Q. en for every positive int eger $If<p$ , we a $Tl_{1}$ $h$ $| \sum_{\leq 1\leq xH}’\chi(Q(xe_{1}+c2))|\leq 2\sqrt{p}\log p+1$ $w\iota_{ler}e\chi$ 1},$ stands for the $q\mathrm{u}$ adratic residue symbol with $\chi(0)=0$ $F_{p}\mathrm{i}’l^{rjth}$ $\iota^{\gamma}e$ , . The proof is routine. Theorem 2. Let $V=F_{\mathrm{p}}[e_{1}, \cdots)e_{m}](m\geq 3)$ be a nadratic space . Then we . have the following assertions: { for some $i,j(i\neq j)$ . Then for any that (i) $(k\neq i, j)$ , there are element. $y_{j}=\pm 1$ and $u\in V$ so that $q$ $Q(e_{i})=0_{\backslash }.B(e_{i}, e_{j})\neq$ $s_{\mathrm{u}pP^{O}}.\mathrm{q}e$ $o\mathrm{V}_{-}^{\rho\Gamma F}p$ $)$ $x_{k}\in F_{l)}$ $\mathrm{s}y_{i}\in F_{p},$ . $v:=yiei+yje_{j}+ \sum_{k\neq i,j}xke_{k}$ $i_{\mathit{8}}$ isotropic a.nd (ii) $B(u.v)’\neq 0$ $Supp_{\mathit{0}\mathit{8}}em\geq 4$ and . $\dim \mathrm{R}\mathrm{a}\mathrm{d}V\underline{<’\backslash }m-3$ . Let be a natural nmber. Then there and a positive number which $r$ $n$ a $su$ bset the following propert. : Let be bsets of and assume that $|S_{1}|=3$ and is a union of at sets of consecutive integers. If $p>c_{r}$ and , then $x_{2}=\pm 1,$ ments for and $u\in V$ such that exist, $T= \{t_{1}, \cdots, t_{4}\}\subset\int_{1}1,2,$ $\cdots,$ $7n_{1}^{1}$ $c_{r}$ $\ddot{\mathrm{b}}at\mathrm{j}sf_{\mathrm{J}}r$ $\gamma$ $S_{1},$ $S_{2}$ $\mathrm{s}u$ $S_{2}$ $F_{\mathrm{p}}$ $\mathrm{m}o,\mathrm{s}tr$ $a\mathit{1}^{\backslash }eele$ $|S_{2}|>5\uparrow\cdot\sqrt{p}\log p$ $x_{1}\in F_{\mathrm{p}},$ $x_{3}\in\llcorner\backslash _{1}’,$ $x_{4}\in S_{2;}*?/j\in F_{\mathrm{p}}$ $v= \sum_{j=1}x_{j\mathrm{t}_{\dot{j}}}4e+\sum_{\tau i\not\in}y\dot{i}ei$ is isotropic and $B(u, v)\neq 0$ . $i\not\in T$ $ther\theta$ 110 To colnbine stories at the infinite prime and at a finite prinue, we need the following. Theorenl 3. Let $S^{(m)}$ be a Let . $p^{9_{m-}}t+1$ $A^{(m)}=$ that for a , ( , $\mathrm{n}a\mathrm{f}$ . $\cdot$ integers with $r<m$ . Le. an let integral matrix an we write be a prim $r\rho,gular\epsilon y\cdot \mathrm{m}metriC$ $D_{1}\in M_{m-\Gamma}(\mathrm{Z}_{\mathrm{P}}),$ $re\mathrm{s}p$ $p$ $r,$ be regula. ) be elementar. divisors of $p^{g_{m}}$ $rm\partial,\mathrm{f},ri_{Ce\mathcal{B}}$ $v$ $A_{1}^{(\cdot,)}||(n-r)m-t$ positi $m$ $S=$ a.Jld suppose th at ) and (resp. $p^{g_{1}},$ be an in tegral matrix with $A_{4}^{(m-r,r)}A^{(}2r))$ $\cdots,p^{t_{m}}$ -r $($ $t_{1}\leq\cdots\leq t_{m}$ $D_{2}$ $D_{1}$ $d$ $\det A=\pm 1$ . . Assume ural um ber , $n$ $e$ $A_{4}\equiv 0$ mod $p^{e},$ $t_{m-,\backslash } \sim<e+t_{1}\leq\min(t_{m}+1, t_{m-r+1})$ $S[A]\equiv$ mod $p^{t_{m}+1}$ have the same elementary divisors and and Then and and both is integral over matrix visors over . $D_{1}$ $S_{4}$ $t$ $\mathrm{v}e$ $d$ $D_{2}\in M_{r}(\mathrm{Z}_{p})$ , and $e\mathrm{n}\iota \mathrm{t}m\mathrm{b}e\mathrm{r}$ $S_{43}^{-1}S$ $S_{1}-S_{4^{-1}}[s_{3}]$ $\mathrm{Z}_{p}$ . $S_{3}\equiv 0$ $D_{2}h\mathrm{a}\backslash \prime e$ mod the $p^{e+i_{1}}$ $\mathit{8}a\mathrm{m}e$ , and the elementary $d\mathrm{i}$ $\mathrm{Z}_{\mathrm{p}}$ Now we can show the following, and by using them we can show the theorem. Proposition 2. Let $M$ be a positi lattice such there is a positive numb er 6 satisf.ring the following conditi on: contain in $gM$ such th at then there is a lattice If , and $\min(M’)\geq p^{1/4}$ . of prim $ep,$ $th_{\partial,t\mathrm{a}}\mathrm{r}\mathrm{n}\mathrm{k}(M)\geq 4,$ $\mathrm{v}e$ ) $\gamma_{\vee}$ $\Lambda’I’$ $>\delta_{f}$ $s(M)\subset p\mathrm{Z}$ $[M’ : M]$ . In the Proposition 2, let is represented by $M_{p}$ by $\mathrm{r}\mathrm{e}_{\mathrm{P}^{\mathrm{r}\mathrm{e}\mathrm{S}}\mathrm{J}}\mathrm{e}\mathrm{n}\dagger \mathrm{e}\mathrm{d}$ $N_{p}$ $N_{\mathrm{p}}$ and that $N$ is a powe $\mathrm{r}$ : $s(\Lambda f_{p}’)=\mathrm{Z}_{\mathrm{p}}$ $Rem,ark,$ . Then be a positive lattice of rank $2m$ and assume tluat is primitivelv is unimodular if $p>\delta$ . Then $N_{p}$ $\Lambda f_{\mathrm{p}}’$ . and $N$ be positi lattices of rank $(\Lambda r)=m\geq 6$ and rank $(N)=$ Proposition 3. is represented by . Then an suppose that , an $dp$ a prime ; represen tecl by is prim if $q\neq p,$ there is a lattice $M’(\supset M)$ such that depends on and where and 1nin $ve$ $I_{J}et\Lambda^{\text{ノ}}f$ $2mreRpeCtiVel_{\mathrm{J}\prime}r$ $num\mathrm{b}e\mathrm{r}_{;}$ $d$ $M_{p}$ $WI_{q}’=lll_{q}$ $( \Lambda I^{f})>c(N_{p})\min(M)^{c}’ \mathrm{p}1$ $N_{p}$ only $on\uparrow n$ $N_{\mathrm{p}}$ ’ $l\mathcal{V}I_{\mathrm{P}}$ $it\mathrm{i}v\theta.ly$ $N_{p}$ $c_{p}$ $c(N_{\mathrm{p}})d..epe\mathrm{r}\mathit{1}dso\mathrm{J}2\mathrm{J}y$ . REFERENCES University Press, 1993. [K] Y.Kitaoka, Arithmetic of $quadrai|c$ forms, quations over $Fin\dagger iep;_{eld}$ , An elementary App roach, Springer Lecture Notes in [S] W.M.S Math, vol. 536, Springer-Verlag, 1976. [V] I.M.Vinogradov, Elemen of Number Theory, Dover Publications, 1954. $\mathrm{c}_{\mathrm{a}\mathrm{n}\mathrm{l}\mathrm{b}_{\Gamma \mathrm{i}\mathrm{d}\mathrm{g}}}\mathrm{e}$ $(_{-}.\mathrm{h}_{1}\mathrm{u}\mathrm{i}\mathrm{d}\mathrm{t},$ $E^{l}$ $i\epsilon$