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Tony Huynh
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The classical finite field Kakeya conjecture state as following (for conveinent, all version of kakeya conjecture is state in hasdorff dimension version):
$\mathrm{Finite\ Field\ Kakeya\ Conjecture}$: Let $\mathrm{F}=\mathrm{F}/\mathrm{qF}$ be a finite field, let $K \subseteq \mathrm{F}^{\mathrm{n}}$ be a Kakeya set, i.e. for each vector $y \in \mathbf{F}^{n}$ there exists $x \in \mathbf{F}^{n}$ such that $K$ contains a line $\{x+t y: t \in \mathbf{F}\}$. Then the set $K$ has size at least $c_{n}q^{n}$ where $c_{n}>0$ is a constant that only depends on $n$.

.....................(*)

The Drir'sDvir's proof toof the finite field version of Kakeya conjecture is elegant and influential. On the other hand, it seems the corresponding version of (*) in $\mathrm{R^n}$ is that,

a set $K$ if satisfied, for every $\theta \in S^{n-1}$ $K$ contain a line $l_{\theta, a_{\theta}}$ and $l$ has direction $\theta$ , then the haussdorff dimension of $K$ is $n$.

But this version in Euclidean space is not essential difficult, in particuler because every line in $R^n$ is not compact and a suitable infinite sequence of line shall group a set which has hausdroff dimension $n$. The original version of Kakeya conjecture in $R^n$ change line to a segement with length 1. So, is there a possibility that a more subtle version of finite field analoge of Kakeya conjecture maybe true? i.e.:

$\mathrm{Version \ 1}$: Fix a sequence $\{a_m\}_{m=1}^{\infty}$, $a_{m} \to \infty$ as $m \to \infty$ and we define a set $K$ in $F_{p_m}^n= (Z/Z_{p_m})^n $ to be a Kakeya set iff for every vector $v\in F_{p_m}^n, v\neq 0 $, such that $K$ contain consecutively(or not) at least $a_n$ point in a line $\{x+t v: t \in \mathbf{F}\}$ for some $x\in F_{p_m}^n$, i.e. contain every direction line with at least $a_m$ elements, then exist $c>0$ only depend on $m$ such that $|K|\geq cp_m^{n-1}$?\

or more easier problem(compare with version 1) but the directly use of polynominal method Invalidation is a following:

$\mathrm{Version \ 2}$: we define a set $K$ in $F_{p_m}^n= (Z/Z_{p_m})^n $ to be a Kakeya set iff for every vector $v\in F_{p_m}^n, v\neq 0 $, such that $K$ contain consecutive(or not) at least $p_m^{\frac{1}{2}}$ point in a line $\{x+t v: t \in \mathbf{F}\}$ for some $x\in F_{p_m}^n$, i.e. contain every direction line with at least $p_m^{\frac{1}{2}}$ elements, then exist $c>0$ only depend on $n$ such that $|K|\geq cp_m^{n-1}$?

for $\mathrm{Version \ 2}$, the polynomial argument gain a bound $O(p^{\frac{m}{2}})$ which coincide with the combinatorics argument two point depending a line. And it is esay to show if take $a_m=2, \forall m \in N^*$ in $\mathrm{Version \ 1}$, then this set $K $ in general do not have full dimension, this corresponde to the situation in $R^n$ when we have a scale $\delta$ kakeya set but instead of $T^{\delta}_{a_{\theta},\theta}$ is a $1\times \delta^{n-1}$ tube, we only have a $O(\delta) \times\delta^{n-1}$ tube.

The classical finite field Kakeya conjecture state as following (for conveinent, all version of kakeya conjecture is state in hasdorff dimension version):
$\mathrm{Finite\ Field\ Kakeya\ Conjecture}$: Let $\mathrm{F}=\mathrm{F}/\mathrm{qF}$ be a finite field, let $K \subseteq \mathrm{F}^{\mathrm{n}}$ be a Kakeya set, i.e. for each vector $y \in \mathbf{F}^{n}$ there exists $x \in \mathbf{F}^{n}$ such that $K$ contains a line $\{x+t y: t \in \mathbf{F}\}$. Then the set $K$ has size at least $c_{n}q^{n}$ where $c_{n}>0$ is a constant that only depends on $n$.

.....................(*)

The Drir's proof to finite field version of Kakeya conjecture is elegant and influential. On the other hand, it seems the corresponding version of (*) in $\mathrm{R^n}$ is that,

a set $K$ if satisfied, for every $\theta \in S^{n-1}$ $K$ contain a line $l_{\theta, a_{\theta}}$ and $l$ has direction $\theta$ , then the haussdorff dimension of $K$ is $n$.

But this version in Euclidean space is not essential difficult, in particuler because every line in $R^n$ is not compact and a suitable infinite sequence of line shall group a set which has hausdroff dimension $n$. The original version of Kakeya conjecture in $R^n$ change line to a segement with length 1. So, is there a possibility that a more subtle version of finite field analoge of Kakeya conjecture maybe true? i.e.:

$\mathrm{Version \ 1}$: Fix a sequence $\{a_m\}_{m=1}^{\infty}$, $a_{m} \to \infty$ as $m \to \infty$ and we define a set $K$ in $F_{p_m}^n= (Z/Z_{p_m})^n $ to be a Kakeya set iff for every vector $v\in F_{p_m}^n, v\neq 0 $, such that $K$ contain consecutively(or not) at least $a_n$ point in a line $\{x+t v: t \in \mathbf{F}\}$ for some $x\in F_{p_m}^n$, i.e. contain every direction line with at least $a_m$ elements, then exist $c>0$ only depend on $m$ such that $|K|\geq cp_m^{n-1}$?\

or more easier problem(compare with version 1) but the directly use of polynominal method Invalidation is a following:

$\mathrm{Version \ 2}$: we define a set $K$ in $F_{p_m}^n= (Z/Z_{p_m})^n $ to be a Kakeya set iff for every vector $v\in F_{p_m}^n, v\neq 0 $, such that $K$ contain consecutive(or not) at least $p_m^{\frac{1}{2}}$ point in a line $\{x+t v: t \in \mathbf{F}\}$ for some $x\in F_{p_m}^n$, i.e. contain every direction line with at least $p_m^{\frac{1}{2}}$ elements, then exist $c>0$ only depend on $n$ such that $|K|\geq cp_m^{n-1}$?

for $\mathrm{Version \ 2}$, the polynomial argument gain a bound $O(p^{\frac{m}{2}})$ which coincide with the combinatorics argument two point depending a line. And it is esay to show if take $a_m=2, \forall m \in N^*$ in $\mathrm{Version \ 1}$, then this set $K $ in general do not have full dimension, this corresponde to the situation in $R^n$ when we have a scale $\delta$ kakeya set but instead of $T^{\delta}_{a_{\theta},\theta}$ is a $1\times \delta^{n-1}$ tube, we only have a $O(\delta) \times\delta^{n-1}$ tube.

The classical finite field Kakeya conjecture state as following (for conveinent, all version of kakeya conjecture is state in hasdorff dimension version):
$\mathrm{Finite\ Field\ Kakeya\ Conjecture}$: Let $\mathrm{F}=\mathrm{F}/\mathrm{qF}$ be a finite field, let $K \subseteq \mathrm{F}^{\mathrm{n}}$ be a Kakeya set, i.e. for each vector $y \in \mathbf{F}^{n}$ there exists $x \in \mathbf{F}^{n}$ such that $K$ contains a line $\{x+t y: t \in \mathbf{F}\}$. Then the set $K$ has size at least $c_{n}q^{n}$ where $c_{n}>0$ is a constant that only depends on $n$.

.....................(*)

Dvir's proof of the finite field version of Kakeya conjecture is elegant and influential. On the other hand, it seems the corresponding version of (*) in $\mathrm{R^n}$ is that,

a set $K$ if satisfied, for every $\theta \in S^{n-1}$ $K$ contain a line $l_{\theta, a_{\theta}}$ and $l$ has direction $\theta$ , then the haussdorff dimension of $K$ is $n$.

But this version in Euclidean space is not essential difficult, in particuler because every line in $R^n$ is not compact and a suitable infinite sequence of line shall group a set which has hausdroff dimension $n$. The original version of Kakeya conjecture in $R^n$ change line to a segement with length 1. So, is there a possibility that a more subtle version of finite field analoge of Kakeya conjecture maybe true? i.e.:

$\mathrm{Version \ 1}$: Fix a sequence $\{a_m\}_{m=1}^{\infty}$, $a_{m} \to \infty$ as $m \to \infty$ and we define a set $K$ in $F_{p_m}^n= (Z/Z_{p_m})^n $ to be a Kakeya set iff for every vector $v\in F_{p_m}^n, v\neq 0 $, such that $K$ contain consecutively(or not) at least $a_n$ point in a line $\{x+t v: t \in \mathbf{F}\}$ for some $x\in F_{p_m}^n$, i.e. contain every direction line with at least $a_m$ elements, then exist $c>0$ only depend on $m$ such that $|K|\geq cp_m^{n-1}$?\

or more easier problem(compare with version 1) but the directly use of polynominal method Invalidation is a following:

$\mathrm{Version \ 2}$: we define a set $K$ in $F_{p_m}^n= (Z/Z_{p_m})^n $ to be a Kakeya set iff for every vector $v\in F_{p_m}^n, v\neq 0 $, such that $K$ contain consecutive(or not) at least $p_m^{\frac{1}{2}}$ point in a line $\{x+t v: t \in \mathbf{F}\}$ for some $x\in F_{p_m}^n$, i.e. contain every direction line with at least $p_m^{\frac{1}{2}}$ elements, then exist $c>0$ only depend on $n$ such that $|K|\geq cp_m^{n-1}$?

for $\mathrm{Version \ 2}$, the polynomial argument gain a bound $O(p^{\frac{m}{2}})$ which coincide with the combinatorics argument two point depending a line. And it is esay to show if take $a_m=2, \forall m \in N^*$ in $\mathrm{Version \ 1}$, then this set $K $ in general do not have full dimension, this corresponde to the situation in $R^n$ when we have a scale $\delta$ kakeya set but instead of $T^{\delta}_{a_{\theta},\theta}$ is a $1\times \delta^{n-1}$ tube, we only have a $O(\delta) \times\delta^{n-1}$ tube.

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katago
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The classical finite field Kakeya conjecture state as following (for conveinent, all version of kakeya conjecture is state in hasdorff dimension version):
$\mathrm{Finite\ Field\ Kakeya\ Conjecture}$: Let $\mathrm{F}=\mathrm{F}/\mathrm{qF}$ be a finite field, let $K \subseteq \mathrm{F}^{\mathrm{n}}$ be a Kakeya set, i.e. for each vector $y \in \mathbf{F}^{n}$ there exists $x \in \mathbf{F}^{n}$ such that $K$ contains a line $\{x+t y: t \in \mathbf{F}\}$. Then the set $K$ has size at least $c_{n}q^{n}$ where $c_{n}>0$ is a constant that only depends on $n$.

.....................(*)

The Drir's proof to finite field version of Kakeya conjecture is elegant and influential. On the other hand, it seems the corresponding version of (*) in $\mathrm{R^n}$ is that,

a set $K$ if satisfied, for every $\theta \in S^{n-1}$ $K$ contain a line $l_{\theta, a_{\theta}}$ and $l$ has direction $\theta$ , then the haussdorff dimension of $K$ is $n$.

But this version in Euclidean space is not essential difficult, in particuler because every line in $R^n$ is not compact and a suitable infinite sequence of line shall group a set which has hausdroff dimension $n$. The original version of Kakeya conjecture in $R^n$ change line to a segement with length 1. So, is there a possibility that a more subtle version of finite field analoge of KalayaKakeya conjecture maybe true? i.e.:

$\mathrm{Version \ 1}$: Fix a sequence $\{a_n\}_{n=1}^{\infty}$$\{a_m\}_{m=1}^{\infty}$, $a_{n} \to \infty$$a_{m} \to \infty$ as $n \to \infty$$m \to \infty$ and we define a set $K$ in $F_{p_n}^m= (Z/Z_{p_n})^m $$F_{p_m}^n= (Z/Z_{p_m})^n $ to be a Kakeya set iff for every vector $v\in F_{p_n}^m, v\neq 0 $$v\in F_{p_m}^n, v\neq 0 $, such that $K$ contain consecutively(or not) at least $a_n$ point in a line $\{x+t v: t \in \mathbf{F}\}$ for some $x\in F_{p_n}^m$$x\in F_{p_m}^n$, i.e. contain every direction line with at least $a_n$$a_m$ elements, then exist $c>0$ only depend on $m$ such that $|K|\geq cp_n^m$$|K|\geq cp_m^{n-1}$?\

or more easier problem(compare with version 1) but the directly use of polynominal method Invalidation is a following:

$\mathrm{Version \ 2}$: we define a set $K$ in $F_{p_n}^m= (Z/Z_{p_n})^m $$F_{p_m}^n= (Z/Z_{p_m})^n $ to be a Kakeya set iff for every vector $v\in F_{p_n}^m, v\neq 0 $$v\in F_{p_m}^n, v\neq 0 $, such that $K$ contain consecutive(or not) at least $p_n^{\frac{1}{2}}$$p_m^{\frac{1}{2}}$ point in a line $\{x+t v: t \in \mathbf{F}\}$ for some $x\in F_{p_n}^m$$x\in F_{p_m}^n$, i.e. contain every direction line with at least $p_n^{\frac{1}{2}}$$p_m^{\frac{1}{2}}$ elements, then exist $c>0$ only depend on $m$$n$ such that $|K|\geq cp_n^m$$|K|\geq cp_m^{n-1}$?

for $\mathrm{Version \ 2}$, the polynomial argument gain a bound $O(p^{\frac{n}{2}})$$O(p^{\frac{m}{2}})$ which coincide with the combinatorics argument two point depending a line. And it is esay to show if take $a_n=2, \forall n \in N^*$$a_m=2, \forall m \in N^*$ in $\mathrm{Version \ 1}$, then this set $K $ in general do not have full dimension, this corresponde to the situation in $R^n$ when we have a scale $\delta$ kakeya set but instead of $T^{\delta}_{a_{\theta},\theta}$ is a $1\times \delta^{n-1}$ tube, we only have a $O(\delta) \times\delta^{n-1}$ tube.

The classical finite field Kakeya conjecture state as following (for conveinent, all version of kakeya conjecture is state in hasdorff dimension version):
$\mathrm{Finite\ Field\ Kakeya\ Conjecture}$: Let $\mathrm{F}=\mathrm{F}/\mathrm{qF}$ be a finite field, let $K \subseteq \mathrm{F}^{\mathrm{n}}$ be a Kakeya set, i.e. for each vector $y \in \mathbf{F}^{n}$ there exists $x \in \mathbf{F}^{n}$ such that $K$ contains a line $\{x+t y: t \in \mathbf{F}\}$. Then the set $K$ has size at least $c_{n}q^{n}$ where $c_{n}>0$ is a constant that only depends on $n$.

.....................(*)

The Drir's proof to finite field version of Kakeya conjecture is elegant and influential. On the other hand, it seems the corresponding version of (*) in $\mathrm{R^n}$ is that,

a set $K$ if satisfied, for every $\theta \in S^{n-1}$ $K$ contain a line $l_{\theta, a_{\theta}}$ and $l$ has direction $\theta$ , then the haussdorff dimension of $K$ is $n$.

But this version in Euclidean space is not essential difficult, in particuler because every line in $R^n$ is not compact and a suitable infinite sequence of line shall group a set which has hausdroff dimension $n$. The original version of Kakeya conjecture in $R^n$ change line to a segement with length 1. So, is there a possibility that a more subtle version of finite field analoge of Kalaya conjecture maybe true? i.e.:

$\mathrm{Version \ 1}$: Fix a sequence $\{a_n\}_{n=1}^{\infty}$, $a_{n} \to \infty$ as $n \to \infty$ and we define a set $K$ in $F_{p_n}^m= (Z/Z_{p_n})^m $ to be a Kakeya set iff for every vector $v\in F_{p_n}^m, v\neq 0 $, such that $K$ contain consecutively(or not) at least $a_n$ point in a line $\{x+t v: t \in \mathbf{F}\}$ for some $x\in F_{p_n}^m$, i.e. contain every direction line with at least $a_n$ elements, then exist $c>0$ only depend on $m$ such that $|K|\geq cp_n^m$?\

or more easier problem(compare with version 1) but the directly use of polynominal method Invalidation is a following:

$\mathrm{Version \ 2}$: we define a set $K$ in $F_{p_n}^m= (Z/Z_{p_n})^m $ to be a Kakeya set iff for every vector $v\in F_{p_n}^m, v\neq 0 $, such that $K$ contain consecutive(or not) at least $p_n^{\frac{1}{2}}$ point in a line $\{x+t v: t \in \mathbf{F}\}$ for some $x\in F_{p_n}^m$, i.e. contain every direction line with at least $p_n^{\frac{1}{2}}$ elements, then exist $c>0$ only depend on $m$ such that $|K|\geq cp_n^m$?

for $\mathrm{Version \ 2}$, the polynomial argument gain a bound $O(p^{\frac{n}{2}})$ which coincide with the combinatorics argument two point depending a line. And it is esay to show if take $a_n=2, \forall n \in N^*$ in $\mathrm{Version \ 1}$, then this set $K $ in general do not have full dimension, this corresponde to the situation in $R^n$ when we have a scale $\delta$ kakeya set but instead of $T^{\delta}_{a_{\theta},\theta}$ is a $1\times \delta^{n-1}$ tube, we only have a $O(\delta) \times\delta^{n-1}$ tube.

The classical finite field Kakeya conjecture state as following (for conveinent, all version of kakeya conjecture is state in hasdorff dimension version):
$\mathrm{Finite\ Field\ Kakeya\ Conjecture}$: Let $\mathrm{F}=\mathrm{F}/\mathrm{qF}$ be a finite field, let $K \subseteq \mathrm{F}^{\mathrm{n}}$ be a Kakeya set, i.e. for each vector $y \in \mathbf{F}^{n}$ there exists $x \in \mathbf{F}^{n}$ such that $K$ contains a line $\{x+t y: t \in \mathbf{F}\}$. Then the set $K$ has size at least $c_{n}q^{n}$ where $c_{n}>0$ is a constant that only depends on $n$.

.....................(*)

The Drir's proof to finite field version of Kakeya conjecture is elegant and influential. On the other hand, it seems the corresponding version of (*) in $\mathrm{R^n}$ is that,

a set $K$ if satisfied, for every $\theta \in S^{n-1}$ $K$ contain a line $l_{\theta, a_{\theta}}$ and $l$ has direction $\theta$ , then the haussdorff dimension of $K$ is $n$.

But this version in Euclidean space is not essential difficult, in particuler because every line in $R^n$ is not compact and a suitable infinite sequence of line shall group a set which has hausdroff dimension $n$. The original version of Kakeya conjecture in $R^n$ change line to a segement with length 1. So, is there a possibility that a more subtle version of finite field analoge of Kakeya conjecture maybe true? i.e.:

$\mathrm{Version \ 1}$: Fix a sequence $\{a_m\}_{m=1}^{\infty}$, $a_{m} \to \infty$ as $m \to \infty$ and we define a set $K$ in $F_{p_m}^n= (Z/Z_{p_m})^n $ to be a Kakeya set iff for every vector $v\in F_{p_m}^n, v\neq 0 $, such that $K$ contain consecutively(or not) at least $a_n$ point in a line $\{x+t v: t \in \mathbf{F}\}$ for some $x\in F_{p_m}^n$, i.e. contain every direction line with at least $a_m$ elements, then exist $c>0$ only depend on $m$ such that $|K|\geq cp_m^{n-1}$?\

or more easier problem(compare with version 1) but the directly use of polynominal method Invalidation is a following:

$\mathrm{Version \ 2}$: we define a set $K$ in $F_{p_m}^n= (Z/Z_{p_m})^n $ to be a Kakeya set iff for every vector $v\in F_{p_m}^n, v\neq 0 $, such that $K$ contain consecutive(or not) at least $p_m^{\frac{1}{2}}$ point in a line $\{x+t v: t \in \mathbf{F}\}$ for some $x\in F_{p_m}^n$, i.e. contain every direction line with at least $p_m^{\frac{1}{2}}$ elements, then exist $c>0$ only depend on $n$ such that $|K|\geq cp_m^{n-1}$?

for $\mathrm{Version \ 2}$, the polynomial argument gain a bound $O(p^{\frac{m}{2}})$ which coincide with the combinatorics argument two point depending a line. And it is esay to show if take $a_m=2, \forall m \in N^*$ in $\mathrm{Version \ 1}$, then this set $K $ in general do not have full dimension, this corresponde to the situation in $R^n$ when we have a scale $\delta$ kakeya set but instead of $T^{\delta}_{a_{\theta},\theta}$ is a $1\times \delta^{n-1}$ tube, we only have a $O(\delta) \times\delta^{n-1}$ tube.

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katago
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Is finite field version kakeya conjecture still true when changing the line of every direction with only 2(or several but not the full line)element?

The classical finite field Kakeya conjecture state as following (for conveinent, all version of kakeya conjecture is state in hasdorff dimension version):
$\mathrm{Finite\ Field\ Kakeya\ Conjecture}$: Let $\mathrm{F}=\mathrm{F}/\mathrm{qF}$ be a finite field, let $K \subseteq \mathrm{F}^{\mathrm{n}}$ be a Kakeya set, i.e. for each vector $y \in \mathbf{F}^{n}$ there exists $x \in \mathbf{F}^{n}$ such that $K$ contains a line $\{x+t y: t \in \mathbf{F}\}$. Then the set $K$ has size at least $c_{n}q^{n}$ where $c_{n}>0$ is a constant that only depends on $n$.

.....................(*)

The Drir's proof to finite field version of Kakeya conjecture is elegant and influential. On the other hand, it seems the corresponding version of (*) in $\mathrm{R^n}$ is that,

a set $K$ if satisfied, for every $\theta \in S^{n-1}$ $K$ contain a line $l_{\theta, a_{\theta}}$ and $l$ has direction $\theta$ , then the haussdorff dimension of $K$ is $n$.

But this version in Euclidean space is not essential difficult, in particuler because every line in $R^n$ is not compact and a suitable infinite sequence of line shall group a set which has hausdroff dimension $n$. The original version of Kakeya conjecture in $R^n$ change line to a segement with length 1. So, is there a possibility that a more subtle version of finite field analoge of Kalaya conjecture maybe true? i.e.:

$\mathrm{Version \ 1}$: Fix a sequence $\{a_n\}_{n=1}^{\infty}$, $a_{n} \to \infty$ as $n \to \infty$ and we define a set $K$ in $F_{p_n}^m= (Z/Z_{p_n})^m $ to be a Kakeya set iff for every vector $v\in F_{p_n}^m, v\neq 0 $, such that $K$ contain consecutively(or not) at least $a_n$ point in a line $\{x+t v: t \in \mathbf{F}\}$ for some $x\in F_{p_n}^m$, i.e. contain every direction line with at least $a_n$ elements, then exist $c>0$ only depend on $m$ such that $|K|\geq cp_n^m$?\

or more easier problem(compare with version 1) but the directly use of polynominal method Invalidation is a following:

$\mathrm{Version \ 2}$: we define a set $K$ in $F_{p_n}^m= (Z/Z_{p_n})^m $ to be a Kakeya set iff for every vector $v\in F_{p_n}^m, v\neq 0 $, such that $K$ contain consecutive(or not) at least $p_n^{\frac{1}{2}}$ point in a line $\{x+t v: t \in \mathbf{F}\}$ for some $x\in F_{p_n}^m$, i.e. contain every direction line with at least $p_n^{\frac{1}{2}}$ elements, then exist $c>0$ only depend on $m$ such that $|K|\geq cp_n^m$?

for $\mathrm{Version \ 2}$, the polynomial argument gain a bound $O(p^{\frac{n}{2}})$ which coincide with the combinatorics argument two point depending a line. And it is esay to show if take $a_n=2, \forall n \in N^*$ in $\mathrm{Version \ 1}$, then this set $K $ in general do not have full dimension, this corresponde to the situation in $R^n$ when we have a scale $\delta$ kakeya set but instead of $T^{\delta}_{a_{\theta},\theta}$ is a $1\times \delta^{n-1}$ tube, we only have a $O(\delta) \times\delta^{n-1}$ tube.